solucionario mortimer 5 ed.pdf
TRANSCRIPT
ji.;ljI'l. ,. l,
ANSWER BOOK FOR MORTIMER'S "
F T F T H T I ' "O I \
,,,1i: ,,r; :'
, : l ' r
,.i, i: ,;' r l : ' 'I l l i :
Í',. :
Lawrenc" M. Epstein
F'
ChapterchapterChapterChapterChapterChapterChapterCl. rpterChapterChapterChapterChapterChapterChapterChapterChapterChapterChapterChapter
123
q,
6
B9
l o11I21 3I4t516L71B1 9
Chapter 20
Chapter 21
Chapter 22
Chapter 23Chapter 24Chapter 25Chapter 26Chapter 27
Contents
IntroductionStoichiometryThermochemistryAtomic StructureProperties of Atoms and the IonicThe Covalent Bondlutolecular Geometry; Molecular OrbitalsGasesLiduids and So1idsSolut ionsReactions in Aqueous SolutionChemical KineticsChemical EguilibriumTheories of Acids and BasesIonic Equil ibr ium, Part IIonic Equil ibr ium, Part I lElements of Chemi-cal ThermodynamicsElectrochemi stryThe Nonmetals, Part I :
the HalogensThe Norunetals, Part I I :
ElementsThe Nonmetals, Part I I I :
Elements
Hydrogen and
The Nonmetals, Part IV: Carbon,Sil icon, Boron, and the Noble Gases
I{etals and Metal lurgyComplex CompoundsNuclear ChemistryOrganic ChemistryBiochemistry
The Group VI A
The Group V A
Bond
I3ti
l 1t7243142496L667 480
90939599
107LL2
119
L 2 71 3 1T4L150155l-73
@ lgg¡ by Wadswor th , Inc . A l l r igh ts reserved. No par t o fthis book may be reproduced, stored in a retr ieval system,or transcribed, in any form or by any means, elecbronic,mechanical, photocopylng, recording, or otherwise withoutthe prior permission of the publisher, Wadsworth publ ishing
Company, Belmont, Cali fornia 94OO2, a Division of Wadsworth,
I S B N 0 - 5 3 r { - 0 e ? e 1 - b
Printed in the United States of America
L 2 3 4 5 6 ' t B 9 1 0 - - - 8 7 8 6 8 5 8 4 8 3
r ' l l / \ [ ' T E R I
I NI ' I ' I iODUCTION
l . i ¡
t l
t . 2
l . ( )
| . t
| . r t
| . , )
¡ . I o
| . r , L
| " t . ¿
l . t l ,
l " l / l
I l ' r
S e e : ( a ) S e c t i o n s 1 . 1 a n d 1 . 2 , ( b ) S e c t i o n L . 2 ,( c ) S e c t i o n L . 2 , ( d ) S e c t i o n I . 2 , ( e ) S e c t i o n 1 . 1
(a) strontium, (b) antimony, (c) aluminum, (d) gold,(e ) s i l ver , ( f ) s i l i con , (g ) mercury , (h ) he l ium,( i ) sod iüm, ( j ) neon, (k ) ca lc ium, (1 ) cadnr ium
( a ) S n , ( b ) T i , ( c ) P , ( d ) K , ( e ) C u , ( f ) C o , ( 9 ) F e ,( h ) I , ( i ) C l , ( j ) c r , ( k ) M g , ( l ) M n , ( m ) L i ,( n ) P b
( a ) 4 , ( b ) I ? , ( c ) I , ( d ) 5 , ( e ) 4 , ( f ) 1 ? , ( g ) 4 ,( h ) 4
( a ) 1 3 7 . 0 , ( b ) 1 0 . 0 0 , ( c ) 0 . 9 0 0 , ( d ) 5 . 0 , ( e ) ] - I 2 ,( f ) 0 . 0 0 2 1 0
- a R - q
( a ) 5 . 9 4 x I 0 ' ,
( b ) 6 . 2 5 x l O - , 3 . 0 x l - O - ,
( d ) O . 0 9 6 , ( e ) 1 3 . 6 , ( f ) 2 . 5 x l O 2
( a ) l O s c m , ( b ) 1 0 - 6 k g , ( c ) 1 0 7 n s , ( d ) 1 O - r 6
r t n
( a ) I o 3 l j - t e r , ( b ) 1 o - 3 m 3
( a ) 1 O - 1 n m , ( b ) 1 0 2 p m , ( c ) 0 . 0 9 9 n m , 9 9 p m
1 . 5 m
l - . 2 1 k m
2 . 8 1 x l o 3 h r , 1 . 1 7 x 1 0 2 d a y
0 . 9 5 4 m 3
9 . 5 9 5 t r i p
236.6 ml sugar , 59 .2 m1 but te r , 394.3 m1 f lour , and1 I 8 . 3 m l m i l k , 7 . 3 9 m l b a k i n g p o w d e r , 4 . 9 3 m I v a n j - 1 1 a ,l - . 2 3 m I s a l t
(a ) 9s" inc rease ' (b ) 6% increase ' (c ) l0g" inc rease
( a ) 5 B % , ( b ) 2 2 K
( a ) 2 o o . 9 P L , ( b ) r ' 2 5 x 1 0 3 g a l l o Y
I . 0 5 x l O 3 g Z n
- 1
4 . 0 x l 0 - a
2OOO g a l loy; 3OO g Cu lef t over ' 60 g Ni le f t over
5L.445 cm/s
A9 km/hr
24.7 hr
r ' l l / \ l " f E R 2
J; , I '0 I CI l IOMETRY
l , , r l _ t g n J = T h e o r y , A t o m i c W
, l . l . See Sect i -on 2 . I .
) . . 2 . S e e S e c f i o n 2 - I .
, l . l A re la t i ve a tomic we igh t i s ac tua l l y a ra t io : theaverage mass of the atoms of an element compared tothe mass of an atom of a standard.
S ince CH+ is 75 .0e" by mass carbon and 25 .0% by masshydrogen, the compound consists of carbon to hydrogenin a mass ra t io o f 3 to 1 . One C a tom, however , i scombined with four H atoms i i-Eu+. One C atom,therefore, must have a mass that is 3 t imes the massof fo_ur H atoms. I f the H atom is assigned a mass of1 .OO, four H a toms wou ld have a mass o f 4 .0O. There la t i ve mass o f the C a tom wou ld be 3 t imes 4 .OO,o r 1 2 . 0 0 .
S e e T a b l e 2 . 1 .
' l ' 1 , , , @
. l . ( ¡ (a ) 24 .7 mol - Hz , L .4g x IO25 molecu les H2
( b ) 2 . 7 8 m o l H z O t L . 6 7 x 1 0 2 + m o l e c u l e s H 2 O
( c ) 0 . 5 1 0 m o l H 2 S O a | 3 . O 7 x 1 0 2 3 m o l e c u l e s H 2 S O a
I . 1 6
1 1 ?
I . I B
1 1 0
* l . 2 1
1 t ?
1 1 A
L . Z 2
L . Z O
1 a 1
1 , Q
6 . 3 8 x 1 0 6 m
pressure is
diamond.
1 t o
r 1 . 3 0
k l . 3 l
k L . 3 2
t I . J J
( a ) 4 6 4 - 5 m / s , ( b ) 4 ' 6 1 x l O 7 m ' ( c )
- 7( a ) f . 3 1 x 1 0
' m ' ( b ) O ' I 3 1 ] r n
O . O 5 7 O c m 3
( a ) 2 . 8 5 c m 3 r ( b ) 4 ' 5 0 c m 3 r n t e n s e
t.qoit .a to transform graphite anto
6 . 4 x 1 0 1 2 g A u
1 . 0 3 x 1 0 3 c m
(a) o . B58 9 , /cm3 , (b ) f loa t
3 . 3 8 0 M m
4 . a 2 2 x L o 2 7 g
t {
( a ) 2 . 9 8 x
( c ) 2 . 1 5 x
4 . 4 8 0 x t _ 0
The atomic
( a ) 4 . 6 1 3 5
( b ) 2 . 7 7 8 3
102 s a toms, (b )
fo24 a toms
g A I
w e i g h t i s 5 8 . 9 3
m o 1 P t , O . 5 2 O 2 4
x 1024 a toms Pt ,
5 . 0 1 x 1 0 2 4 a t o m s ,
( the e ]ement i s Co)
mol Ir
3 . \ 3 2 g x l - 0 2 3 a t o m s I r
rl-
2.LL (a ) 0 .14393 mol Au ' 8 '6676 x 1022 a toms Au
(b) 1 .3335 x 1020 a toms Au
l_.29 l ! = 3; the formula is CuSOr¡ . 3H2O
* 2 . 2 9 V C l 3
l'-r.lrcentage Composition
:¿ . 30 34 .42 N i in N i (co) q' ) . .3L
69 .592 Ba in BaCO3t
2 .32 49 .762 Z r i n Z rS iOa
;¿ .33 629 g Zn
' 2 . 3 4 2 . 0 0 k g C u
i .¿_. l l_ 0.6334 9 Xe¡ 0.3666 s F
, t . 3 6 2 . 9 A 9 9 L i , 2 . 0 1 1 9 N
2 - 3 7 A 2 . 8 % C , 1 7 . 4 e " H
* 2 . : 1 9 8 3 . 9 e " c , l 2 . O B H , 4 . l z o
r , ) . . 39 a4 .64% Fe2o3 i n o re
* : 1 . 4 0 1 . 5 5 4 S i n o i l
r'!!.rcmlgaI *Equations
').-!! (a) VzOs + 2Hz + VzOs + 2H2O
(b) 282iu^3 + 7C -> BaC + 6CO
(c) 4Bi + 3O2 -> 2Bizos
(d) CaCz + 2H2O + Ca (OH) 2 * H2C2
(e ) Ba (NOg)z '+ HzSO+ + BaSOq + 2HNO3
. ' . .42 (a) 3NO2 + H2O + 2HNO3 + NO
(b) Al2S3 + 6H2O -> 2AL (OH) 3 + 3H2S
(c) 3SiC1a + Si -> 2Si2C15
(d) (NH'+)zCreOz + 4HzO * Cr2O3
(e) Ca3N2 + 6HeO + 3Ca(OH) 'z + 2NHg
They would extend 6'022 x 1018 km' which is over
4 x 1O1o t imes the distance'
*2.L3 2.22 aüoms Cv
Formulas
2 . L 4 ( a ) H g B s S o ¡(e ) C+Ha
2 .L5 (a ) CoS ' (b )(e ) PsNsCI r o
(b ) NazSzo '+ ,
B z o H r e r ( c )
( c ) V r S + r (d ) NaePeOz '+ '
S + N 2 , ( d ) N e S e F s I
2.L6 f, ien'*
2 . 1 7 C 1 ¡ H 1 2 O N
2 . I B C 2 H 6 N
2-Lg ca5P3013H or cas (Por+) g (oH)
2 . 2 0 C e H s O a
2 . 2 L C e H l ¡ N O a
2 . 2 2 C e O z H s
2 . 2 3 C 7 H 5 0 3 S N
2 . 2 4 ( a ) O . 2 l O m o l C ' 0 ' 3 5 0 m o l H ' ( b ) C s H s r
(c ) 2 '87 g CsH5
2 . 2 5 ( a ) 0 . 3 6 o m o l c ' 0 ' 3 6 0 m o l H ' 0 ' 0 9 0 0 m o l S-
( b ) C r + H + S , G ) 7 ' 5 7 g C + H + S
t c2 .26 (a ) 0 .389 mo l C ' 0 ' 389( b ) 4 . 6 7 I c ' 0 ' 3 9 3 I( c ) L ' 7 7 g , ( d ) 0 ' 1 1 1
2.27 x = 6; the formula is
m o l H , 0 . 0 5 5 5 m o l N
H , 0 . 7 7 7 g N
mol O, (e ) CzHzNOz
CoCl2 ' 6H2O
4
t 2 . ! 2
2.43 (a) 2CsHr s + 2502 + l6COz + IBHzO
(b) CzHeO + 3Oz -> 2COz + 3Hzo
Note that the combustion of ethyt alcohol requires
less oxvge"';t;-;; i" of fuel thán the combustion of
oclane does'
Problems Based on Chemical Equations
2 . 4 4 1 3 8 . 1 I H 3 P o a
2 . 4 5 ( a ) 6 - 0 0 g N a N H 2 ' 3 ' 3 8 I N 2 o ; ( b ) 1 ' 3 1 I N H 3
2 . 4 6 5 . 3 2 g K N o 2 ¡ 2 ' L L g K N O 3 ¡ 3 ' L 7 q C r z o g
2 . 4 7 3 . 2 6 g H r
2 . 4 A ( a ) 2 - O 7 ' l g A s , ( b ) f 5 ' 5 % A s a o 5 ' ( c ) 1 1 ' 7 e " A s
2 . 4 9 7 3 . 7 2 N a 2 S O 3
2 . 5 o 4 - 9 9 g N H 4 s c N
2 . 5 L 1 . O B g F 2
2 . 5 2 L . L O 7 9 B z H o
2 . 5 3 1 . 2 9 I S F ¡ r
2 . 5 4 4 . 3 3 g o P ( N H e ) e ¡ B 0 ' 8 %
2 . 5 5 ( a ) 0 . 2 9 5 6 9 T i ' ( b ) 3 ' B O 7 g T i C l 3 ' ( c ) 7 8 ' 8 0 % v i e l d
2 . 5 6 ( a ) 1 ' 9 4 $ N a N 3 ' ( b ) 6 1 ' 9 % Y i e l d
r '2 .57 45 .0% Bao in mix tu re
*2 .58 62-Os" CaCO3 in rn -Lx ture
* 2 . 5 9 L 5 - 2 % C a C O 3
Reactions in Solut ion
2.60 22L g H2Soa
. l . 6 1 1 0 7 . O g K I O 3
. , . . 6 2 1 5 . 0 g N a O H
, ' . . 6 3 1 6 . 0 m l H 3 P O a s o l t n
' . ' . . 6 4 7 5 . 0 m l A g N O 3 s o l ' n
. l .65 5. O0 ml KI4nO¡+ so1 'n
. ) . . 6 6 0 . 8 4 2 g C a O
: . 6 7 2 . 8 6 g 1 2
. f . 6 8 ( a ) O . 4 6 4 9 . N a 2 C O 3 , (b ) 37 .Le" Na2CO3
CHAPTER 3
TIIERMOCHEMISTRY
l .
r {
r 0
_12
- 1 0 8 1 . 6 k J
- 7 L . 4 k J
3 . 3 1 - 2 7 2 7 . 8 k J
, ' 3 . 3 3 - 6 2 2 k J
Heat Measurements, Calorimetry
3 . 1 3 7 " C
3 . 3 - 4 0 0 c
3 . 5 L . 3 6 k J / o C
3 . 7 1 3 9 k J
3 .9 L44 J
3 . 1 1 2 6 . 7 4 0 C
1 . 1 3 8 7 3 k J
3 . 1 5 2 . 2 5 k J / o c
3 . 1 8
3 . 1 9
3 . 2 0
3 . 2 2
L 9 . 4 2 k J
+ 7 6 . 3 k J
La\^/ of Hess
3 . 2 4 + 5 0 . 0 k J
3 . 2 6 - 3 0 0 . 1 k J
3 . 2 8 - 1 3 7 6 . O k J
- L 7 . 7 8 " C
1 8 . 8 k J
2 . 4 6 J / ( 9 " c )
2 3 - 4 7 " C
9 2 . 2 g
2 . 7 5 x r o 3 k J
0 .907 g CtzÉzzOt t
Thermochemj-cal Equations
3.17 (a) endothermic, (b) exothermic' (c) endothermic'
(d) exothermic
1 Ec6H6 (1 ) *
7o , (g )+6COz (g )
czHsoH (1) + 3Oz (g)+2coz (S)
l , ; rr_f halp_iss of F_ormation
f - .34 (a ) Ag( " ) + +c lz
(g ) + Aec l (s ) AS = - r27 k r, l
( b I J N z
( g ) + o z ( s ) + N o z ( g ) A + = + 3 3 . 8 k J
(c ) ca (s ) + . c ( s raph i t e ) n 1o1 ' | ¡ - l
+ caco3 ( s )
A+ = -L2O6 .e kJ
1 r1 .35 (a )
TuzG) + c (g raph i re ) +
i * r t g l + HcN(g )
A H : = + 1 3 0 . 5 k J--{
c ( s raph i t e ) + 25 (s ) -> cs2 ( f ) A+ = +87 .86
?N z ( g ) + 2 H z G ) *
i o r ( S l + N H q N o s ( s )
A H : = - 3 6 5 . 1 k J"'t
J - , 1 9 - 1 1 2 5 . 2 k J 3 . 3 7 + 9 6 . B k J
t . 3 B - I 2 I 2 . 3 k J 3 . 3 9 - 8 4 7 k J
l : i 9 ( a ) C H 3 o H ( 1 ) + ; o r ( s ) + c o 2 ( q ) + 2 H z o ( r )
( b ) - 7 6 4 . L k J
r . 4 I ( a ) c 5 H 5 ( 1 ) r + o r ( g )
+ 6 c o z ( g ) + 3 H 2 o ( l )
( b ) - 3 2 6 7 . 7 k J
t - . 4 2 ( a ) N 2 H a ( 1 ) + 0 2 ( g ) + N z ( g ) + 2 H z o ( L )
(b ) +50.6 kJ /mol -
\ . 4 3 ( a ) c o ( N H e ) e t s l + * o z ( s )
- ' c o 2 ( g ) + N z ( s ) + 2 H 2 o ( 1 )
(b) -333 kJ,/mo1
1 . 4 4 - 1 6 3 . 0 k J , / m o l 3 . 4 5 - 3 5 I . 5 k J l m o l
t . 4 6 - 6 2 . 8 k J , / m o l
3 . 2
3 . 4
3 . 6
3 . 8
3 . 1 0
3 . L 2
3 . 1 4
3 . 1 6
( b )
( c )
KJ+
f
3H2o( l ) Ag = - ¡Z6a
3Hzo(1 ) AH = -1368
6 9 . r k J
383 kJ , 45 r kJ
+ 8 1 . 5 k J
- 1 4 9 . 9 k J
- 3 1 9 . 5 k J
3 . ¿ L
3 . 2 3
5 . ¿ )
3 . 2 7
3 . ¿ Y
Bond Energres
3 .47 -92 kJ i i n Tab le
3 .48 +96 kJ
3 . 5 0 - 2 0 6 k J
3 . 5 2 1 5 3 k J
3 .54 -23 kJ
3 . 5 6 - 3 3 0 k J
3 . 5 8 ( a ) - 1 5 0 k J
3 . 5 9 ( a ) - L 9 2 4 k J
AH: o f Hc l (g ) i s---f
3 . 4 9 + 1 1 2 k J
3 . 5 1 + 1 3 2 k J
3 . 5 3 - 1 2 1 k J
3 . 5 5 - 1 2 0 k J
3 . 5 7 - 1 2 8 8 k J
(b ) -1s9 kJ
(b) -1915 kJ
*92 .3O kJ lmo l .J . I ¡
r ' l l A l ' T E R 4
A'I'0MIC STRUCTURE
Nu_
4.L Both charge and mass determine the degree ofde)f l-ect ion of an electron from a straight- l ine pathin an electr ic or magnetj-c f ield. I t is impossibleto investigate either factor separately usingThomsonrs_method.
4 . 2 ( a ) H - , l i g h t e r m a s s
(b) l¡e2+, higher charge
* 4 . 3 ( a ) I . 8 2 x l 0 r + g , / c m 3
( b ) I - 3 2 x 1 O l 8 g
4 . 4 S e e T a b l e 4 . 2
4.5 Since Z = 29 for Cu and Z = 79 for Au, the posit ivecharge-of the Au nucleus is higher than the posit ivecharge of the Cu nucl-eus. Consequently, more wide-angle deflections \^rere observed r^rhen the Au foi-l wasused.
r 4 _ : 9 2 . 7 c m
n 4 : l 2 . 2 x l o - r 2 a
4 . 8 ( a ) 5 6 e l e c t r o n s ;
, n o( b )
- : : B it J J
4 . 9 ( a ) 7 8 e l e c t r o n s ;
A¿,(b ) I ^zn
J U
nuc l -eus : 56 protons, 82 neutrons
nucleus: 78 protons, 1I7 neutrons
10 11
t 5
2 2
3 7
80
5 8
26
35
l5
22
3 7
80
g23
36
I6
26
!?L 2 2
ó z
_J U
44
iir
II
4.LO Symbol
P
Ti
Rb
H9
U E
- 3 +H ' é
"t-
4.11 Sl¡mbol
K
Mn
Zr
Pb
Xe2 -
q Á
cd2+
Z A
15 31
22 4A
3 7 8 5
80 202
58 140
26 56
3s 12
Z A
19 4L
25 55
40 90
a2 204
54 L32
3 4 q
48 1r4
ElectronsProtons Neutrons
Protons Neutrons
19 22
25 30
40 50
a2 L26
5 4 7 8
34 46
4A 66
(a) infrared radiat ion,
(c) microwaves
4 . 2 2 1 . 1 3 x l o l s / s
4 .23 (a )
(d )
4 . 2 4
4 . 2 5
4 . 2 9 x L o r a / s , 2 . 8 4 x l o - r e J
7 . 5 0 x L o L + / s , 4 . g 7 x 1 o - r e J
l l lectromagnetic R
4 . 2 1 , (b ) b lue l igh t ,
4 .32 1875 nm
Electrons
I 9
2!
*54
36
46
( a ) 3 . o o x r o 2 o / s , L . 9 9 x 1 o - r 3 J
( b ) 3 . o o ' x l o l L / s , l . g g x L o - 2 2 J
( a ) 3 3 3 m , 5 . 9 7 x 1 0 - 2 8 , l
( b ) 2 5 0 n m , 7 . 9 6 x 1 0 - 1 6 J
4-26 251 photons
4 . 2 7 4 3 s
*4 .28 L . lA x : . o r s , / s , 263 nm
jiliI
I
4 . L 3
Isotopes' Atonic Weights
( a ) A , E ; B , D ; C , F , ( b ) A , B i C r D ; E , F ;
,^ , , 54.^ 54n- 5or , 50.- _ 53"o _ 53v(c )
26 r ' e , 24u t t 23u ' 24 - t ' 26 ' - ' 23 '
* 4 . 2 9 ( a )
(b )
( c )
^!9mag_gpegtra
4 . 3 1 9 7 . 2 4 n m
4 . 3 3 n = 6 . \ = 2
- l q
4 . 9 7 x 1 0 - -
J- l q
3 . 5 9 x 1 0 - -
J
5 .41 x Lo r+ 7s ¡ 555 nm
4.L4 The unit based or, 12",
the current standard'
4.Ls oo.tszsr\v and o.zstl lv
4.16 oz.otzLlTuxe and :z-soalf lne
4. t i s2.5%1Lí and z.sa lu
4 . 1 8 6 9 . 7 2 u
4 . I 9 2 0 . 1 8 u
4 . 3 4
* 4 . 3 5
* 4 - 3 6
(a) u l t rav io let , v is ibte, v is ib le
(b) n = 2 '+ a = f ¡ rr = 4 + g = 2, !_ = 3 + n = 2
2.279 Um corresponds to the transition n = @ to n = 5.
7.459 Um corresponds to the transition n = 6 to n = 5.
2 . L ' : . g x 1 0 - 1 8 J(a ) 3 .289 x LOrs / s , ( b )
(c) 1.3: -2 x 103 k. r /mol
L2 I3
r r 4 . 3 7
* 4 . 3 8
( a )
( c )
( a ) K = ( 3 . 2 8 g x L O t s / s ) z - 2 - , ( b ) 1 ' 3 1 6 x 1 0 1 6 ' / s
4 .50 (a ) 18 (en t i re n = 3 she l l - ) , (b ) imposs ib le (when
a = 3 , 1 c a n n o t e q u a l 3 ) , ( c ) I 0 ( 3 d s u b s h e l l ) ,( d ) 2 ( a 3 d o r b i t a l ) , ( e ) 2 ( 3 s s u b s h e l t ) ,( f ) imposs ib le (when I = 0 , ml cannot equa l +2) .( g ) 6 ( 3 p s u b s h e l l ) .
4 . 5 1 ( a ) 2 ( 4 s s u b s h e l l ) . ( b ) i m p o s s i b l e ( w h e n I = 0 ,m 1 c d o n o t e q u a l + 3 ) , ( c ) 2 ( a 4 f o r b i t a l ) ,(É) 10 (4d subshe l l ) , (e ) imposs ib le (when n = 4 ,I c a n n o t e q u a l 4 ) , ( f ) 1 4 ( 4 f s u b s h e l l _ ) , ( S ) 3 2 ( t h ee n t i r e n = 4 s h e l l ) .
2 . g 6 L x 1 0 1 6 / s , ( b ) 1 O . B O n m ,
7 2 . 9 3 n m , 5 4 . 0 2 n m
Periodic LlLw
4 . 3 9 S e e S e c t i o n 4 . 1 0
4.4O Mende leevperiodicMoseleYperiodic
4 .41 X rays a retransitionsn = 1 o r
* 4 . 4 2 z = 2 a - o , 2 B N i
* 4 . 4 3 0 . 2 2 7 r w
ouantum Numbers
stated that the propert ies of elements are
functions of lncreasing atomic weight '
showed that the properties of elements are
functions of atomic number'
bel ieved to be produced by electron
to levels deep within the atom (to the
n = 2 l e v e l ) . S e e S e c t i o n 4 ' 1 0 '
4 . 5 2 ( a ) 9 ,
4 . 5 3 ( a ) 2 4 ,
( b ) 1 7 , ( c ) 8
( b ) 1 2 , ( c ) 4
4 .54 l s 2s 2p 3s 3p 3d 4s
26-" 1' 1L 1L 1' 1t lt 1t 1L 11, 1t 1 1 1 1 1'
I
i
I
i l
rliI
i i
I i l -ectronic Confiqurations
r"' zz' zg' :g' ¡t' 396 4='
4 . 5 5 S e e S e c t i o n 4 . 1 3
4 . 4 4
4 . 4 5
* 4 . 4 6
4 . 4 7
4 . 4 8
4 . 4 9
See Sect ion 4- I2
See Tab le 4 -4
( a ) 0 . O 2 4 3 r : m . , ( b ) 3 . 5 1
S e e F i g u r e s 4 . 1 5 , 4 . L 7 t
S e e S e c t i o n 4 . 1 1
m-.-sL 1 / )
- 1 / )
+ 1 / ,
-L/2
+ 1 / )
4.:9_ (a) rzcJ- t (b) 2 5MN,
4 . 5 7 ( a ) s + X e , ( b ) + B C d r
4 . 5 8 ¡ T C L t 2 5 M n ¡ 6 3 E u r 7 7 T r
can be checked by re fe r r ing to Tab le 4 .8 .
( c ) 6 , ( d , 2 , ( e ) 1 , ( f ) 0
are paramagnetic
can be checked by re fe r r ing to Tab le 4 .8 .
( c ) 2 o c a ,
( c ) 6 3 E U r
( d ) 3 o Z n l
( d ) 7 t T r ,
(e ) 3 5Kr
( e ) g s B a- 3 6
x 1 0 m
and 4 . IB!.32
!.So
4 . 6 I
The notations
( a ) 0 , ( b ) 2 ,
b , c , d , a n d e
The notat ions
- 1 m '
l l n
Z L
a | + l
2 L 0. I - ' lZ L
n l m l
1 0 0
1 0 0
2 0 0
2 0 0
r ' l +1
m
+' l / )
+- l / )
- - t /2
- 1 / )
4 . 6 2 ( a ) 2 t ( b ) 4 , ( c ) 3 , ( d ) 4 , ( e ) 0 , ( f ) 0 , ( g ) 2
&, b , c , d , and g are paramagnet ic
L L4 15
4.63 (a) 4zAgrz rs2 2s2 z{ z t 3d1o 4s2 4d6
: " ' ¡gu 3q l o 4s2 496
5 d l o 6 s 2
( c ) z r sc3+ , l s2 zZ ' zg .u ¡g t 3q6
CTIAPTER 5
I)ROPERTIES OF ATOMS AND THE IONIC BOND
Atomic Radii
5.1 !{ i thin a giroup the atomic size increases withincreasing atomic number because the valence shell¡5rincipal quantum number n, increases. Recall thatin the Bohr atom, x = n2 x .059 nm. Ba ) Sr forexample. Within a period the atomic size for themain groüp elements decreases with increasing atomicnunber because the valence shell quanturn number isconstant whilst the effect ive nuclear charge increasesand draws the electrons closer in. p < Si.
5.2 Within a period, the main group metals are larger thanthe non-metals, as explained in 5.1 above. Howeverthe transit ion metals are smaller, because after thed shel l is f i l led the nonmetal-s add to the nextquantum level.
5.3 The init ial effect of entering the transit ion seriesis'a shrinl<age because of the increase in nuclearcharge, while obtaining minimal shielding. The higherthe I quantum number, the less effective theshielding. However as the d shel l approachescompletion i t becomes an effect iüe shield between thenext quantum shell and the nucleus.
5 . 4 ( a ) S i > S ( b ) S n > S i ( c ) c a ) S i , b e c a u s e G a ) G eand Ge ) S i (d ) A l > S i (e ) M9 > S i ( f ) s ¡_ ) C l ,and Cl > F so Si > F (g) Si > C. Al l above in accordwi th ru les in p rob lem 5 .1 .
5 .5 A lso fo l low ing above ru les : (a ) po ) 1s , (b ) p > S ,(c) Ba > Sr (d) Sr > Sb (both are main group
e lement .s ) , (e ) fn > Sn ) Ge, ( f ) pb > B i( S ) K > C a > M g .
1 i . 6 2 3 2 p m
? ñ " 4 d r 0
4 d r 0c -l-
(b ) s2Pbz+ z l s l 2s r
4fL4 5s2
( d ) z + C r 3 + : l s 2 z t '
( e ) 1 6 S 2 , l q 2 z Z '
2p6 3g' 396
2t tz' 3g6
3 d 3
3dr o 4s2 ¿gt ¿d t o
( e ) 0 ' ( f ) 0 ,
t ^ 6
( n "
(f) 53r : t t zt 296 3x2 39:
s"' sg'
4 . 6 4 ( a ) O , ( b ) o , ( c ) o ' ( d ) 3 'I
Liii
only d is Paramagnetic
4 . 6 5 S e e S e c t i o n s 4 . 1 3 a n d 4 . 1 4
4 . 6 6 2 E C t t z g C u r q l N b ¡ t + 2 M o t 4 3 T c r 4 + R ü ¡ 4 5 R h ¡ 4 6 P d ¡
47Ag¡ 54Gdr 78Pt , and 79Au ' Ha l f - f i l l ed subshe l l :
Cr , Mo, Gd. F i l led subshe l l : Cu, Pd, A9 ' Au '
4 .67 (a ) representá¿ ive , meta l , (b ) representa t ive ' non-
meta l , (c ) t rans i t ion , meta l , (d ) representa t ive '
meta l , (e ) inner t rans i t ion , meta l , ( f ) nob le gas '
norünetaI
16T7
4.63 (a) +zAg*, Lt ' z" ' zgt 3" ' ¡p t gqto 4" '
(b) s2pb2+ 2, t"l z"l 2bt 39' ¡p6 ¡al o 42'
¿ l t u s " t sp6 sa to os2
| i l / \ 1 , ' l ' L lR 5
T' IT{) I ' I IRTIES OF ATOMS AND THE IONIC BOND
,¡uic Radii
r , . l . Vüithin a group the atomic size increases withincreasing atomic number because the valence shellprincipal quanturn number n, increases.
'Recall that
in the Bohr atom, x = n2 x .059 n{n. Ba > Sr forexample. Within a period the atomic size for themain group elements decreases with increasing atomicnr¡nber because the valence shell quantun number isconstant whilst the effect ive nuclear charge increasesand draws the electrons closer in. p < Si.
' , .2 Vüithin a period, the main group metals are larger thanthe non-metals, as explained in 5.1 above. Howeverthe transit ion metals are smaller, because after thed shel l is f i l led the nonmetals add to the nextquantun leve1.
' , .3 The in i t ia l ,e f fec t o f en ter ing the t rans i t ion ser iesis'a shrinkage because of the increase in nuclearcharge, while obtaining minimal shielding. the higherthe 1 quantuñr number, the less effective theshielding. Hor^rever as the d shell approachescompletion i t becomes an effect iúe shield between thenext quantum shell and the nucleus.
' . 4 ( a ) S i > S ( b ) S n > S i ( c ) G a ) S i , b e c a u s e G a ) G eand Ge ) S i (d ) A1 > S i (e ) Mg > S i ( f ) s i ) c l ,and Cl > F so Si > F (g) Si > C. A11 above in accordwi th ru les in p rob lem 5 .1 .
' , .5 A lso fo l low ing above ru les : (a ) po > Te, (b ) p > S ,(c) Ba > Sr (d) Sr > Sb (both are main groupe l e m e n t s ) , ( e ) I n ) S n ) G e , ( f ) p b > B i( S ) r > C a > M g .
' ; . 6 2 3 2 p m
496 4dr o
ap6 aar o
a +( c ) 2 1 S c " - : I s 2
1 +( d ) z , * c r " - , 1 s 2
( e ) r 6 5 2 : l s 2
( f ) E 3 I : t " '
srt
4 . 6 4 ( a ) o , ( b ) 0 ,
zt ' 2t : " '
2* 2p-G :"'
2sz 296 ¡" t
zZ' zg' ¡"t ¡gt
5p6
3 p 6
? n 6 t ¡ 3
e ^ 6
3 d r o 4 s 2 4 p o 4 d l o
( c ) O . ( d ) 3 , ( e ) o ' ( f ) 0 ,
only d is paramagnetic
4 . 6 5 S e e S e c t i o n s 4 . 1 3 a n d 4 . 1 4
4 . 6 6 2 t + C x , 2 9 C u , 4 ¡ N b ¡ 4 2 M o ¡ 4 3 T c ¡ 4 4 R u ¡ 4 5 R h , 4 5 , P d ¡
47Ag¡ 54Gdt 78PEt and 7eAu. Ha l f - f i l l ed subshe l l :
Cr , Mo, Gd. F i l led subshe l l : Cu¡ Pdr Ag, Au.
4 .67 (a ) representá t ive ' meta l , (b ) representa t ive , non-
meta l , (c ) t rans i t ion , meta l , (d ) representa t ive '
meta l , (e ) inner t rans i t ion , meta1, ( f ) nob le gas '
norunetal
L6L7
Ionization EnergY
5.7 The f i rs t ion iza t ion energy fo l lows a t rend jus t
opposite to that of atomic size. There are anomalies
in the f irst two periods however as explained in
p r o b l e m 5 . 1 0 .
5.8 Because metal atoms are general ly larger than non-
metals their ionization energies are 1ower.
5 .9 cou lomb 's law is E = q l -92 . cons ider 9 r to be -1 ,
the charge on the electron, and q2 the charge on the
ion left behind after removing the electron. Since
q2 = +2 for the second ionization, and +1 for the
first, the second ionization energy must be at l-east
twice the first. Note that r may be the same or^^^^ . ih ] . , r ^SS fOr the Second ion iza t ion , bu t never} , U D J T U ! ) ' ¡ s
greater since the outermost electron is the f irst
removed.
5.10 The sequences Be-B, and N-o, 90 contrary to the trend
across a period, because although Be ) B in size the
electron removed from B is a p electron, higher in
energy than the s electron removed from Be. The
electron removed from O, unl ike that from N, is one
of a pair occupying a single p orbital and is subject
to electron-electron repulsion which makes i t easier
to remove (again despite the smaller size of o).
5.11 Fol lowing the usual trends (a) Sr > Rb (b) Sn > Sr
(c ) Sb > Sn (d ) Sb > B i (e ) Se > Te > Sn( f ) S > S e ( g ) A r > S
5. I2 A l l fo l low the usua l t rends except O vs- N wh ich is
exp la ined in 5 .10 . (a ) Ne > o (b ) Ne > Ar
(c ) o > S (d ) F > C l > S (e ) l ¡ > o (anomalous)
( f ) M9 > Na (g ) Mg > Ca
Elect]:on Aff ini tY
5 .13 I t requ i res the expend i tu re o f 1680 kJ o f energy to
remove a mole of electrons from a mole of gaseous
fluorine atoms to form a mole of F+ ions. When a
mole o f e lec t rons jo ins a mole o f gaseous f luor ine
atoms to form a mole of F- ions, 322 kJ of energy
is l ibera ted .
14 Wi th in a per iod there is a genera l inc rease in theenergy l iberated by electron attachment because theatoms are gett ing smaller and the attached electroncan get cl_oser to the nucleus. The same anomaliesd iscussed in 5 .10 occur , and are re la t i ve ly impor tan tbecause we are concerned with energíes much less thanioni-zation energies. Thus beryl l ium (which mustattach a p electron) is so far out of l ine that tneattachment reaction is endothermj"c. (posit ive signi n t a b l e 5 . 2 . )
Down a group dif ferences are relat ively small andunpredictable. Attachment energy is expected to beless exothermic for a larger atom but this effect isoffset by the reduced electron-electron repulsion inthe larger atom.
r , .15 The pos i t i ve s ign ind ica tes tha t energy must beexpended to forcibly attach an extra electron to theatom. The attachment reaction is endothermic ratherthan exothermic which is more conmon.
' , . 1 6 ( a ) s > C I i n s i z e ; e l e c t r o n c o m e s i n c l o s e r t o C 1and more enefgy is l iberated. (b) p must put i tsextra electron into an already occupied orbital andovercome electron-electron repulsion which detractsfrom the exotherm. (c) As noted in 5.14 Be must adda p electron. which is much further out than the se lec t ron added to L i .
' -L7 A1 l negat ive ions res is t the a t tachment o f anadd i t iona l e lec t ron ( l i ke charges repe l each o ther ) .One must expend energy to force a second electron toa t tach ; reac t ion is endothermic .
, - lB (a ) Na is la rges t . (b ) Ar has the h ighes t f i r scionization energy. (c) Na is the most reactive metalbecause i t has the lo\^¡est ionizati .on energy.(d ) C l i s the most reac t ive nonmeta l . (e ) a r i sleas t reac t ive hav ing a l l i t s va lence orb i ta ls f i l l ed . .( f ) The meta ls a re the th ree e lements Na, Mg, A I .
IB 1 9
Latt ice En-ergy, Bgrn-Haber Cycl_e
5 . 1 9 - 8 2 4 k Jmole
5 . 2 r - 3 0 1 0 k jmole
5 . 2 3 - 3 2 4 k J m o l e - l
5 .24 K CI < K2O < CaO. Choose K2O over K C1 because o f
Ereater charge and smal le t ' s tze o f 'o2- . Choose Cao
over K2O because of greater charge and smaller size
- ^ 2 +
5.25 The la t t i ce energy is usua l ly the guant i t y o f g rea tes t
magnitude and mast be large enough to compensate for
the large amount of energy required to ionize the
rnetal atom, which is usually the next most importanta ' r ¡ n + i + r zY s s ¡ ¡ e ¡ s t .
The lonic Bondr T)¡Pes- of Iols
, . r l t (a ) a l l pa i red , d iamagnet ic
(b) 4 unpaired electrons, highly pararnagnetic
(c) three unpaired electrons, paramagnetic
(d) thro electrons unpaired, paramagnetic
(e ) a l l pa i red , d iamagnet ic
( f ) a l l pa i red , d iamagnet ic
,.2.() A simpli f ied way of writ ing configurations of largeatoms is to use a noble gas symbol for the'config-uration of most of the electrons, as shown in thearls\¡/ers below.
( a ) s 2 - 1 s 2 2 s 2 2 p 6 3 s 2 3 p 6 o r s i m p l y : t A r l
(b ) cu+ Ls22s22p63"23p53dr 0 o r : [Ar ] 3dr 0
(c ) cu2+ tAr l 3de^ ¿
( d ) S c 5 ' [ A r ]
( e ) F [ N e ]
( t ) sg2+ lxe ] 4 f r q5d10 (Not " txe l s l ¡mbo l inc ludes
. rhe 5p6¡
( 9 ) p b 2 + [ x e ] 4 f t 4 5 d I o 6 p 2
( h ) c r 3 + [ A r ] 3 d 3
. lO (a ) a l l pa i red , d iamagnet ic
(b ) a l l pa i red , d iamagnet ic
(c) one d orbital has an unpaired electron,paramagnetic
(d) al l paired, diamagnetic
(e) al l paired, diamagnetic
(f) al l paired, diamagnetic
(g) the p electrons are in separate orbitals, t \^¡ounpaired, paramagnetic
(h) three unpaired d electrons occupying separateorbitals, paramagnetic
.11 (a ) [Kr ] j . soe lec t ron ic w i th Se2 , Br - , pJc+, s r2+, y3+
(b) l zn?+) r G^3+, cu+, ce¡+ , (uncommon)
2 L
5:2O '2]152 kJ mole-r
5 . 2 2 - 6 0 3 k J m o l e - I
5 . 2 6 N a 2 O N a C I
Mgo M9CI
Na3N
Mg gNe
AlzO¡ AIC13 A1N
N L
5.27 (a ) l tg t ' rs¿2s2 2p6
(b) c r2+ rs22s22p63r23p63da
4 r(c ) coz* rs22s22p63s23p63d7
( d ) p d 2 + L s 2 2 s 2 2 p 6 3 s 2 3 p 6 3 d 1 0 4 = 2 4 p 6 4 d 9
( e ) A g + L s 2 2 s 2 2 p 6 3 = 2 3 p 6 3 d r 0 4 " 2 4 p t 4 d r 0
( f ) r r s ? 2 s 2 2 p 6 3 s 2 3 p 6 3 d r 0 4 " 2 4 p 6 4 d 1 0 5 = 2 5 p 6
Same as xe
2 0
(c) lznJ : Gar, Ge+2
( d ) [ o 2 - ] , F , N e , N a t , M g 2 + , A 1 3 + , N 3 -
( e ) [ c . 2 + ] , K i , s " t f , A r , c l , s 2 - , P t - , l i n *
5 .32 (a ) [ ca2+ ] r r r3+ , s r ru+ , Ag+
(b) [as+] cd2+, rn3+, srn*
( c ) t n ¡ + l K r , B r , s . 2 - , s t ' * , Y t *
(d ) tHs l r 1+ , Pbz+
(e ) I xe l r e2 - , r - , c r * , Ba2+ , L .3+
5,33 s2 io r r= a re ra re , no negat ive "2 io t t a re poss ib le
except H- rs2 . L i t and Be2t a re a lso rs2 . The sc
group never loses just 1 electron- Only others are
the d l0s2 l i " t "d be low. To summar i r " s2 : H- , L i+ ,
8.2+; t2p6 very comrnon, including most nonmetal
negative ions and the posit ive metal ions of main
g r o u p s r r r r r a n d I I I . E x a m p l e s o 2 - r ' F - , N a + , M g ' * ,
A13+; ¿10 ions inc lude a l l the zn group, " .q . zn 'n ,
a n d m a i n g r o u p r r r , e . g . G . 3 + ; a l s o s n + + , P b t 4 ; a l s o
cu+, Ag+, Au+. Negat ive i -ons aren ' t poss ib le .
d r 0 s 2 i o n s a r e r r r * , T l * , s r r ' + , P b 2 + , A " 3 * , s b 3 * ,
ano rJl-
5 . 3 4 A 1 ' * , G . ' * , S " 3 + , N ' � - , K + , B a 2 + , a t e S 2 p 6 i o r r s .
P b i + , T 1 + , B i 3 + , a r e d l o s 2 l o n s .L ' +
c u * , c d " , a r e d l o i o t t .
5.35 Addit ional energy is requ.ired to form'Cu2+ compared
to cu+, but this is not extreme because the second
electron is from the 3d she11 which is close to the
4s shel l in energy. The addit ional energy is more
than compensated for by the greater latt ice energy
in the case of crr2*. rn the case of N-tf , the second
electron must come from the 2p shel l , fat below the
3s in energy, and the energy requirement is so great
that it cannot be compensated for by the additional
latt ice energy of the hypothetical Na2+ ion.
, . i t J ( a ) C r z O g
(c) Ag2Cr2O7
(e) l¡ i (Nog ) ¡
, . l ' . ) (a ) Fe2 (SO+ ) e
(c ) Ba (oH) 2
(e) PbCrOr
( b )
( d )
( f )
( b )
( d )
( f )
, . 4 0 ( a ) m a n g a n e s e ( I I ) s u l f a t e
(b) magnesium phosphate
(c ) lead ( I I ) carbonate
(d) mercury (I I) chloride
(e) sodium peroxide
(f) aluminum sulfate
, .41 (a ) ca lc ium perch lo ra te
(b) coba l t ( I I ) n i t ra te
(c ) t in ( I I ) f luor ide
(d) potassium permanganate
(e) iron (I I1) phosphate
( f ) mercury ( I ) iod ide , o r
' . r r , ( a ) C s , ( b ) S - , ( c ) S - ,
t , . t " l ( a ) B r , ( b ) C s , ( c ) 0 2 - ,
rrrr,,r.rclature of Ionic _Cs¡mpounds
(d ) c r2+ , (e ) Ag , ( f ) As
(d ) au+ , (e ) T1+ , ( f ) r n+
Ca3 (Poh ) 2
Mg (c1o3 ) 2
ZnCO3
/ - r r Pr
A u 2 S 3
N H a C 2 H 3 0 2
dimercury di iodide
2 3
, , . ' , ( a ) H - ñ - ó - Ht "I
ü
( c )
4 . .v , : O -
( e ) H -
( a ) ¡ r - 3
( e ) , i t , i ,l l
. . 1 t . ., . { - 3 - 3 - I ,
. . 4( a ) : o : V
IO , o - J @ - ó , O" l
I: 9 : A\-/,
.. /a\( c ) : o : v
| . . ¡ a1 , 4 , c ¡
- Q , V\-/, I' Y '
Oc\ ..
( e ) V : o :l ^
, \ : ó - j @ - ; , o\ 7 " |
"
' Y ' O
( b ) : C l - o - C l :
( d ) : N = C - C = N :
- 0.9
H
covalent compounds, Lewis structures
6 . 1 H z , N z , C - 2 , F z , C L z , B r 2 ¡ f 2 r ( S 2 k n o w n a t h i g h
temperatures)
6.2 Ba Br2 must be ionic (opposite sides of the periodic
table), containing Ba2+ and Br- ions. The simplestformula is always given for ionic compounds.
A A(a) ,ñ-c=tt, , :Fg=C-ñ:KJ structure I is better
because it minimizes formal charge. In additionstructure 2 is poor because N gained a negative
charge at the expense of the more electro-negative F
I
l G )C I V
II
' Y O
o - o -
- L I :
6 . 3
( b ) : C l :It . .
t "I
' q ] ,
( d ) , r ,t ^.. I l2+l
/ - 1 : N - S V - F :t z - t\-/ |
( c ) H
t . .H - C = O :(b) " r . .@21
"/*-*\o'ro
- ';'O"\@@z:'N=N Structure I
. / \ . r : rH .b.'v
is better because there is less formal chargeseparation. In addition structure 2 is very poorbecause it requires the same sign of charge onadjacent atoms.
6 . 4 ( a ) H - C f N : ( b ) H -
( c ) H ( d ) H -
IH - S i - H, )
H
( e ) H - ñ - r ¡
IH
( b ) H
" - l@- ó ,ot "
, 9 , O
(d ) , ó , O
| '. ¡'�:\o ' T - O ' "
' 9 'o
24
6 . 8 ( a ) H - N - N - Ht lt l
U E
( c )
* @ - I ,
.'aÍ'
\ ^N \ 7 - F :
( b ) H - N = N - H
(a) O ,ó
p r . r r r r l I d , f I C €
t , . l . t Resonance is invoked in cases where a pair ofelectrons is not local ized to the bonding region ofa particular pair of atoms, so that the f.ewisstructure scheme is inadequate. Such a molecuLe is
( e )
. F - N I - \ T - F ." I | "
t t
. n l - c - q - ñ ] .
a resonance hybrid, for which the best we can do toshow its structure is to draw various resonance forms.
The structures H-C=N: and H-N=C: represent trt¡od i f fe ren t mo lecu l_es w i th d i f fe ren t ske le tons , i .e . ,dif ferent sequences of attachments of atoms. Inresonance forms the positions of the atoms areidentical, only the electrons are shif ted.
If one atom has a formal charge of 1r, no ad.jacentatom may bear a formal_ positive eharge.
ra . . @.. @..o- :N=p=N-H +-> :NIp_N_H
H-ó-Ñ=É, this structure is,-sufficient, but a possibleresonance srructure is H -@A = ñ - i ; ,O; whicrrhowever cannot be as important as the unchargedstructure
n - O ñ - s @ = [ ¡ < - - + H - ñ = i i @ - ó , O B o r hstructures important, no uncharged structure possible.A -o . . ev :g-P=N: *-* ,9=n'=¡, O
, ! -ñ , O @,s=¡ ,l l * ' l l
:N=s :6 O
' l ! -F ,A A+ +
, S -m,< - > l l l
. tT_c -o ' , , : 'oc\ ..(9
. Y :O-N-Cl,{+
ll
6 . s t . l O , c = o , O : l ¡ = o : O O r c = N , : N = N :
(b) carbon nitrogen carbon either nitrogen
O.:;.* *
' \
, /
6 . 1 0 ( a )
, . /
o..o..( b ) , ó = Ñ - I ,
( d ) o , ñ = 3 @ - F ,
6 . 1 1 ( a ) H - N - C = N :II
H
o ' e - @ t \ . .
F :
l a ' l . F r - N T = T r I - F .
Compound (a) requires us to show resonance struc
( b ) : C I :I
. - l
: C l - C = O :
( c ) H - i l - Ñ = ó ,
(d) .. G) ..o o.. o .. oo.. o: O = N - O : : O - N - O : : O - N = O :
l " + " l l < : + " 1,9 , ¿ . , O: ,9 t A'
\J \,'
( " ) q H - c : N : + - + , é = c = Ñ , O
Resonance is indicated by double-headed arrow, +->
( c )
O , s - ñ , Oi l l
ót , l / : O = N - C I :
I' Y ' O
¿ o 2 7
6 . 1 8
A.. \9
6 . L E H - N = N = N :
4 . .6.2o \ ' l :o-c=N: <-+
6 . 2 4 ( a ) C u C l z ,
( f ) A I 2 S 3 ¡
6 . 2 5 ( a ) L i g P r
( f ) F e 2 S 3 , ( 9 ) I n 2 S
6 . 2 6 B o n d i s 5 . 8 6 % i o n i c
6 . 2 7 B o n d i s 1 5 . 3 % i o n i c
structure.
o o . . @r + - > H - N - N f N :
A:o=c=N: \./ The left form, whi-ch has
(b ) MgSe, (c ) L j - I , (d ) PbCl ¡ * , (e ) CdIz '
(g ) SnIz
( b ) B e B r z , ( c ) A u 2 0 3 , ( d ) S n B r z , ( e ) A g z S ,
: F - N - N = O :" lI
: F :
This structure is sufficient.
fY
. . g / . . . . a:F - N = 5 - 6, tr . / A possible resonance structure,"
I which however cannot be asI
,Ir important as the uncharged
r , . . ! l IF > BrF > C1F > ICI > IBr ) BrC l
r, . .r ' ) Electron aff ini ty is the energy of electron attacrunentand can be measured precisely, either direct ly orindirect ly (Born-Haber cycle). Electronegativi ty isa dimensionless numerical rat ing of an element'stendency to draw electrons to i tself . I t is anapproximation dependent somewhat on the judgement ofthe person who worked. out the rating scheme.original ly (Mull iken scale) i t was based on an averaseof ionization energy and electron aff ini ty; thecurrently popular pauling scale is based on bondenergy. In any case i t is electronegativi ty whj_chassesses the total character of the atom and thusprovides us *IEñ-T guide to judging how polar a bondwi l l be .
,. lO CS < OCl < CCI < OC = SO < InI < A1S < BeI < SiO< CaS < AlO < Cacl
Use A for electronegativi ty dif ference bel_ow.6 . z L O , ó - ñ = ó , < - > , ó = ñ - ó , O
- ó , O
the negative charge on the more electronegativeatom, wÍl- l make a greater contr j-bution to lheresonance hybrid than the right-hand form.
6 . 2 2 H - C = O : # H - CI II t
: O : , a O :" \:,/
6.23 :O=C=C=C=O: This form i-s suff icient. Other lessimportant forms wíth formal charge are shownbelow.
O,ó-"="-c=o,@ *- t @:o=c-c=c-ó, O
Bonds of Inüermediate Characterr Electronegativity
a) NaBr ,b ) N B r ,c ) P B rd ) P Se) Pbr
A = o-.8A = 0 . 4A = 0 . 4
IOnlcCovalent, nearly 0B ionicCovalent, perhaps 10% ionicCovalent, sl ightly ionicSuggests covalent. However pbl2i s s a l t 1 i k e , 4 O O o C ,suggesting ionic. A is a poor
F \ D u
g ) B H
criterion in this case.A = 0 Covalent, nearly O? ionicA - .2 Covalent, very l it.t le ionic
h )i )
t , . 1 2 a )
b )
c )
d )p \
f l
s)h )i )
characterB Br A = 1.0 Covalentr perhaps 17? ionic l ike HClB a B r A = 2 . I l o n i c
C a O L = 2 . 4 I o n i cC O A = 0.8 Covalent perhaps 108 ionicC10 A = O.2 Covalent very low polari tyC Cl A = 0-6 Covalent sl ightly ionicC Mg A = 1.3 Covalent very polarC s O L = 2 . 6 I o n i cC S A = 0 C o v a l e n t v e r y l o w p o l a r i t yC I A = 0.1 Covalent very 1ow polari tyC H A = 0.4 Covalent very low polari ty
¿ ó 29
.e6 . 3 3 ( a ) C H m o r e
€(c ) FS more
<i-->(e) FS more
Nomenclature of Covalent -Binary_Compounds
6 . 3 4 B f F s ' S 2 C L 2 , P q N + ¡ T e F 5 , S s N e
6 . 3 5 P r + O o ' B F 3 ¡ C l 2 O 3 ¡ X e F 4 , I z O z
6.36 a) phosphorus pentachlorideb) iodine pentoxide, or di iodine pentoxidec) si l icon tetraf luorided) sulfur tr ioxidee) tetrasulfur tetranitr ide
6 .37 a) su l fu r hexaf luor ideb) tetraphosphorus tr isulf idec) d. ichlorine heptoxide, or chlorine heptoxided) si l icon dioxidee) dinitrogen tetraf luoride
t , l l A l " l ' l l l { 7
,llr 'tll,AR GEOMETRy; MOLECULAR ORBITALS
@NO contai.ns an odd number of electrons so one atommust be content with only seven electrons. In p C15there must be l0 electrons around p to form the fívebonds to the chlorine atoms. In N the octet cannotbe exceeded because for n = 2 there can be only fourorbitals. and. at most eight electrons; whereas forP, where n = 3, there can be as many as nine orbitalsand 18 electrons (although rarely more than 12).
AB2 l inear
Ab3 planar triangle
AB2E bent
ABa tetrahedron
AB3E trj.angular pyramid
AB2E2 bent
AB5 trigonal bipyramid
AB4E an irregular four_sided figure that may beca l led a "saw-horse"
o r a , , see_saw, , ,
AB3E2 T-shaped
AB6, octahedral
AB5E square pyramid
AB4E2 square planar
(a) AB+ tetrahedron, (b) AB5E square pyramid,
(c ) AB2 l inear , (d ) AB2E bent , (e ) aesn t r iangu larpyramid, (f) AB3E tr iangular pyramid. (9) ABaEdistorted tetrahed.ron or "sa\¿-horse,,, (h) AB3E2T-shaped, ( i) ABs tr igonal bipyramj"d
polar
polar
polar
( b )
( d )
( f )
<+OHeOHeNH
more polar
more polar
more polar
30 31
7 . 4 See previous problems for Lewis structures
(a) BHa sp3 (b ) XeFsf d2upt (c ) Bec lz sp
(d) sbF2? sp2 (e ) snc l3 sp3 ( f ) AsH3 sp3
(g) TeFa dsp3 (h ) rF3 dsp3 ( i ) s iF5 dsp3
TlBra ABa tetrahedron+
XeF3 ' AB3E2 T-shaped
SClz AB2E2 bent
AsF2- AB2E bent
GaI3 AB3 tr igonal Planar
C1F4- AB¡rEz sguare Planar
PBra ABaE distorted tetrahedron or "saw-hor
TeF5 AB5E square pYramid
sbFs2- AB5E square pyramid
T lBra- sp3 (b ) xer3+ dsp3 (c ) sc12 sp3
AsF2+ sp2 (e ) Gars sp2 ( f ) c rFa dsp3
p B r a - d s p 3 ( h ) t e F 5 - d 2 s p 3 ( i ) s b F s 2 - d 2 " p 3
Bicls- AB5E square Pyramid
SeF5 AB5E square PYramid+
C1F2 AB2E2 bent
InC12- AB2 straight
BeF3 AB3 tr igonal Planar
GeF2 AB2E bent
AsFa ABaE d.istorted tetrahedron, or
4 . .O e S C l z V : O :
A ,é -
* @ - i i , ABa sp3 re r rahed ron
v l. r ' l .
tó = 3 - ii, AB3E sp3 rrigonat pyramidII
' 9 ] '
:O = C - Cl: AB3 sp2 tr igonal planarII
. ^ 1 .
t3 = C = 3r AB2 sp l inear
+ ^( c ) s e F s ' s p '
( f ) CdBrz sp( i ) s i F 6 z - d 2 s p 3
AB2IJ2, sp3, bent. . 4O: v AB3E sp" t r igonal
pyrardd
( a )
( b )
( c )
( d )
( e )
( f )
(s )
( h )
( i )
sbF4 -
+AsCla
.
+q a É ' ^
XeF4
CdBr2
IJJ- I 4
I.Br2
" . i o . - 2 -
s D I 4 d s p - ( b )x e F a d 2 s p 3 ( e )B i r a - d s p 3 ( h )
C 1 2 O : C l - O -
? -
'
. . ;A s O 3 - : O v -
(d) osc l2
(e) oCclz
ABaE distorted tetrahedron, or "sa$/-
horse "
ABa tetrahedron
AB3E tr igonal pyramid
ABaE2 square planar
AB3E tr lgonal pyramid
AB2 straight
ABr*E distorted tetrahedron or , 'saw-
horse"
AB2E3 l inear
486 octahedron
7 . 5
7 . 7
( a )
( b )
( c )
( d )
( e )
( f )
(s)( h )
( i )
( a )
(d )
(s)
\ 4 , 1
( b )
( c )
( d )
( e )
(s)
( a )
( d )
(s )
i l ,A S -
I
,¿,O
( a )
A s C 1 4 - s p 3GeF3 sp3IBr2- dsp3
7 . 6 / . t I
( f )
t . t - 2 ( a )
( b )
( c )
(h) xeFz
( i ) A lH+
" savt-horse "
AB2E3 l inear
ABq tetrahedron
(a ) e i c r s2 - d2sp3 (b ) se rs d t "p t ( c ) c rFe+
(d) InCl2+ sp (e) BeF3- sp2 ( f ) GeF2 sp2
(9) AsFa- d,sp3 (h) xer2 dsp3 ( i ) A lHa sp3
sp3
csz
: o :tl
. . t l: C 1 - P - C l :
" I
I: C l :32
AB4 sp3 tetrahedron
(b) ,ó = s l - i i ,
4 . .( c ) v : o - C = N :
Not. tn.t onfyconsidered. The
the form: ,ó -/ñ
,a\ .. \Y( d ) ' ' ' : o - N - F :" l l
I I
o :
- É \ . .( e ) C 1 0 g v : O -
AB2E sp2 bent
AB2 sp l inear
one resonance form need be
same results wi l l be deduced from
c = Ñ , O
AB3 sp2 tr igonal Planar
i i @ - ó, O AB3E sp3 tr ieonal|
" ^ , , r ¡ m ; A
, ¿ , O
. , r l q s ¡ ¿ u
sp3 bent
O,ó ,(a ) o3c1oc1o3 (c lzoz)O,A - " l@
o, l ,
o,ó ,(b) o2NoNoz (NzOs )
( d ) F N N F : F - N = N - F : N ' s
a re abou t I 20 " . N = N ¡o r ra i "
,6 , O- ó - " l@- u ,"
, l 'o
. ." "p2 so NNF angles
r ig id so molecu le i s
Each C l i s sp3 (ABa) so the molecu le cons is ts o f twote t rahedra jo ined a t a corner (cent ra l O) .
ó , O. . @- o - N (and
reson-anceforms)
Each N is sp2 (AB3) so the molecu le cons is ts o f twot r iang les (w i th N a t cen ters ) jo ined a t a corneroxygen. Free ro ta t ion is a l lowed.
(c ) HONO(HNOz) H - ó - Ñ = ór N is sp2. Non l inear
mol-ecule with ONO angle of about 12Oo and NOH angleof alput 1O9.5o. Freely r+Lating so .four atoms arenot coplanar.
:
\
\oN
/
( e )
( f )
" , j ,o
"pyramid
H C N H - C = N : A B s P l i n e a r
/?l.. .. 1Cr - A .:XeO3 v:O - Xe \-/ - ó, \J or tó = i i: = ó"
" t " l ll r ñ l l
: O : V O :
AB3E sp3 tr igonal Pyramid
Note that the use of the alternative Lewis
structure with expanded octet (d-p 1T bonding)
makes no difference in the ileduction of the s
34
cop lanar w i th e i ther bo th F 's on same s j -de (c is ) o roppos i te ( t rans . ) .
(e ) c lssc l ,q i - :
- :
- q i ' s ' s a re sp3. Mo lecu le
i s non l - inear and f ree ly ro ta t ing a t a l l jo in ts . A f ta n g l e s a r e a b o u t 1 0 9 . 5 0 .
ó',tl¡ l
(a) oXeFa r i i - i ie - i i , Xe is d,=p, 1or sp3d2) ," / t/ \,
, ' f , . AB5E square pyramid' I '
(probably most stabl-e with O opposite the unsharedp a i r )
(b ) (HO) s IO, a lso wr i t ten Hs106 and ca l l_ed per iod ica c i d .
,ó g" - ó ,O AB2E sp2 bent
. . . . 4,ó = i i - ó , \ 7 AB2E2 sp3 ben t
2 - O , ó - 3 O - ó , O A B 3 E s p 3 r r i e o n a l
(b ) Seo2
( c ) c I O e
(d ) so3
H
" - lo- a,ot ",¿,o
AB4 sp3 tetrahedron
3 5
( c ) O S F 4 : F
w 2
ó ,fl
" l l
H - O - I - O. . , / t \
. t a l ' .
V . ^ . V/ / ' : u : \
/ I \H l
H
Á .t lI
- s -
- H I i s d2sp3¡ AB5 oc tahedronaround I with O at corners.H atoms rotate freely from
. . 5 corners .n
F : S l s d s p " , A B s , t r i g o n a l"
bipyramid (probably most: stable with O in axial
posit ion) .
k1 , ' , , r l . ¡ r Orb i ta ls r p lT-dT Bond ing
(ols and O*ls are shown only for Li2 to C2)
L íz Bee 82
++o*2s
t+o2s
++o * 1 s
t+o ls
B . O . = 0 ,
diamag.
- o z
oup
t f _f i*2p r*2p
+ +1t2p 1t2p
++o * 2 s
t+o2s
t+o*1s
t+o l s
B . O . = 1 rparamag.
F . ^
++o * 2 s
t+o* I s
B . O . = 2 ,diamag.
++tt2p
t+1T* 2p
t+T2P
++Tr2p
(d) (HO) '+XeOz n _ ^ . ?,., _ ",i,, -/ "í
n" 9'
o"'
' n / "
/ 4 ,-\. Á., , \ ' '
n
++o2s
++o*1s
t *ols
B . O . = 1 ,
diamag.
N2
o-rp
, ' *Zp tT-rp
t +;-r
t+
++o2s
f +
Xe is d"p3 , A86 oc tahedra l a r rangement o f o rscent ra l Xe, 4 dang l ing Hrs f ree ly ro ta t ing .
7.16 The Cl bonding pai-rs are more voluminous, and thusare more I ike1y to be equatorial where there are o2 neighboring pairs at 90o, rather than axial wherethere are 3 neighboring pairs at 90o. One couldargue that having them both axial would minimizerepulsions between the C1 bonding pairs, but theconsideration of 90o neighbors is more important.The least likeIy arrangement is to have the Cl bondqat 90o to each other (one axial Cl and one equatora'] \
f+ ++Tf 2p T2p
++lfrp
o-rp
f+r*2p
f+ffrp
7 . L 7 : X - P - 2 t :I . .I
X :
The unshared pair drives the X's closetogether, in an effect which wil l bemost pronounced for X = Fr because theP - F bonding pairs occupy the least
offer least resistance to being pushed
o2p
t+o*2s
++o 2 s
B .O .=3 r d iamag .
++62p
++6 * 2 s
++
B . O . = 2 , p a r a m a g .
t+o2p
++6 * 2 s
++62s
B . O . = f ,
volume andtogether.
36 37
diamag.
7 . I 9 ( a ) H z
o -1 t
t + .- 1 ^v ! >
B O = 1
+7 . 2 A O z '
+ 1 + t +
+( D J i l 2 (c ) HHe
+
( d ) H e z ( e ) H e z +
+ + +
1+
_L2
w 2
ñ*oJ(
T* firt , lT¡tfI ¡t
t+o o
!
w2
t+ ++TT 1T
3
á o
0 2 o z 2 -
O r k O * o?t
f+ t+,lT t TfJ<
++ ++,TT 1I
d *
t+ ++1T 'II
B O = 2
C2 is isoelectronic ( i f we disregard the order of
o a n d n o r b i t a l s ) w i t h N 2 , N O + , C N , a n d C O .N2 and CO are the neutral isoelectronic molecules.
+co co' co No
t + + + + t1T.- TiT- 1T*- F-- nf- tT.-
r + f + f + + + + + J +1I 'IT 1T 1T 11 1T
( b )
( c )
d t k
tT- tT-
r+ ++
U
B o = 3
+NO
¿ áparama9.
NO
paramag.¿z
paramag.
++o
B O = 2 ¿paramag.
7 . 2 L N 2
t *
2parama9.
ÍN 2
^ - t ,-;-
L 2
paramag.
t+
1diamag.
Oz Qz
++f +t +t ++*
t+++t +t+
ft+,IT
1T.
t+1I
T : t
^ 1 az z ¿
t
t+
ó la 2
t+
t+++++ñ
B O = 3
Since distance var ies inversely \ , r i th B-o. N2 is. | . +
sho r t e r t han N2 ' and 02 ' i s sho r t e r t han 02 .
++ ++
+l
B O = 3
++ t+
++
2paramag.
3 B 39
4 . . . . a7 . 2 4 \ J : O - N - O : < - - + : O = N - O : V T h e r e s o n a n c e
show the negative charge shared between the twooxygen atoms and the bonds intermediate betweenand double bonds.
Alternatively we can say there is a sigrna bondbetween N and each O and that 2 electrons are in adelocal ized TI bond connecting al l three atoms.
7 . 2 s O , ó - ó O = ó : + - + , ó = ó @ - ó , O " o , r u i s b e r w e e n
a single and a double bond.
O , 6 - S @ = ó : + - + , ó = B @ - ! i , g s i m i r a r r o o zcaser however there is a preferable structure whi
has no formal charges :O = S = O¡ . This isal lowable for sulfur, a 3rd period element, whichuse i ts d orbitals to exceed the octet rule, notpossible for oxygen. Furthermore, a sl ightcontribution from the minor resonance forms:
, ó = É O = o , @ - * O : o = O ' s = ó ,
suggests that the bonding is even stronger thanbond, so that it is even shorter than the d.oubledistance. There are also contr ibutions from theforms:
O,a - ' s = o ,O. . - *O:o = B - ó ,O
which average to the double bond. Multiple bondingby sulfur, when the octet rule is exceeded isattributed to d-p pi bonding.
7 .26 In add i t ion to th is s t ruc tu re , ,ó ,V
, óO- sL - ó , O" I é i 't 9 r -
si l icon a third period element may exceed the octetru1e. There are four minor resonance forms such as
O . 6 -
which j-ndicate some mult iple bondinS (d_p pi bonding)thus shortening the bond length. Note that sincethese four forms put negative formal charge onadjacent atoms they must be very minor contr ibutions.
7 , - ' I PHs Expect bond length = 1OO + 32 = I42 pm, jusr asfound experimental ly.
PFs Expect bond length = 1l_O + 64 = I74,than found. The actual bond is shortenedbonding using d orbitals on p (3rd period)suggested by three resonance forms like
much greaterLr<r z l -n ^ iV J V } / } J ¿
A S
: F - i l o= Fot "
: o :il
, J O - a , Ot "r A
4 04 T
C}IAPTER B
lsJ¿J
Sj-mpl_e Gas Laws
8.1 (a) At constant temperature the volume of a gasvaries inversely with i ts pressure.
(b) At constant pressure the volume of a gas samplevaries direct ly with the absolute (Kelvin) temperat
(c) At constant volume the pressure of a gas samplevaries directly with the absolute (Kelvín) temperat
4 . 2
lst l ine 22.4 l- íEer, 2nd I j .ne3rd l ine 1 .633 mole , 4 th l ineatm
(b ) 3 .45 a tm .
9 , 5 1 l i t e r
0 .496 a tm .
44.8 J,l-Ler,27 .5K , 5 th l i ne I L .76
8 . 1 8 L . 3 4 s " + -I l_Éer
t t . l ' l 5 . 9 7 l i t e r
r l . L9 .4 '74 arJm.
i l . . , l l - 34 .19 mole
i l . .13 58 .09 mole
( a )
( c )
6 . 5 5 a t m .
4B5K o r 2L2aC
J ' 1, . , r l cas La\^I
r t . L 2
u . l 4
l t . L 6
2O5 m1.
619K or 346aC
8 . 1 3
4 . 2 0 3 9 0 K
4 . 2 2 8 0 . 9 9
^ r 1 1 a o ^
_ - I
mol.e -
1'"{-.1 ' r i r r c i p l e
t t . . ) .4 30 . O0 l i te rs CHa requ i red , 45 .0 l i te rs 02 requ i red ,3O.O l i te rs NH3 requ i red , 90 .0 l i te r " HrO(g) p roduced
l | . : i 5 1 0 . O l i t e r s H C N
t t . . ' . 6 4 N H 3 ( 9 ) + 5 O 2 ( S ) - r 4 N o ( 9 ) + 6 H z o ( g ) 4 0 . O
t t - . ) . J 4NHg (g) + 302 (g ) + 2Nz (g ) + 6H2o(g) ; -2 .s
¡ r . . l B 0 . 5 0 l i t e r C l 2 r e m a i n 1 . 5 0 l i t e r N 2
9 . O O l i t e r N H 3
; r . . 1 9 ( a ) 3 N O - > N 2 O + N O 2 ( b ) 8 3 . 4 m I t o t a l
(c ) P" ,^ = p . . ^ = O.5OO atm.I \U2 N2U
I t , l 0 ( a ) 4 N H 3 ( 9 ) + 3 F 2 ( g ) + N F s ( g ) + 3 N H a F ( s )
( b ) 1 0 0 0 m l N H 3 , 7 5 O m l F 2 .
l i t e r s N o ( 9 )
l i ter N2
t"lL"""2,""V ,rt,L" - t
- l
8 . 3 ( a ) 7 5 0 m 1 .
(c ) 15Oo ml .
A . 4 G ) L 2 . 0 a t m .
( c ) 4 . O 0 a t m .
8.5 1000 bal loons
8 .6 7 .46 x 10 -6 acm
8 . 7 ( a ) 4 . 0 4 l i t e r
( c ) 1 1 7 . 2 K o r - 1 5 6 " C
B . B ( a ) 1 7 1 m 1 .
( c ) 3B2K o r 109 "C
8 . 9 0 . 9 1 6 m 1 .
8 . 1 0 ( a ) 2 . 3 4 a t m .
( c ) 2 2 3 . 5 K o r - 4 9 . 5 " C
(b ) 150 m l .
(b ) 0 .120 a tm .
352K o r 79 "C
2 lBK o r -55oC
( b ) 1 4 9 0 K o r L 2 L 7 " C
( b )
( b )
42
8 . 3 1 5 . 7 L g l i t e r - r 8 . 3 2 5 8 . 0 g m o l e - l
8 . 3 3 ( a ) 1 . 2 0 x l o r a l i t e r
( b ) 3 . 2 3 x 1 0 3 6 m o l e c u l e s
8 . 3 4 ( a ) B . O x 1 O - s S ( b ) L . 2 5 x 1 0 - 6 m o l e s S o 2
( c ) 2 . 8 x 1 0 I
a t m ( d ) 2 . 8 x 1 0 - 6 g .
8 . 3 5 ( . ) n " O = 8 . O O x 1 0 6
a t m a t 2 7 3 K
( b ) 2 . 1 5 x 1 O r 7 m o l e c u l e s
( c ) B . O 0 x 1 O - + %
Stoichiometry and Gas Volumes
8 . 3 6 ( a ) 4 N a ( s ) + 3 N e O ( g ) + N H 3 ( 1 ) + N a N s ( s ) + 3 N a o H ( s )
+ 2Ne (g)
(b ) 12400 ml Nzo
( c ) B 2 7 o m l .
Note : Answer in tex t i s O.K. bu t d i f fe ren t becauseequation (a) can be balanced in more than one way.
8 . 3 7 ( a ) 2 H C N ( q ) + N o 2 ( g ) + C z l ¡ z ( 9 ) + N o ( g ) + H z o ( g )
(b ) ml HCN = 5600 ml . r m1. NO2 = 2BOO ml .
( c ) 2 8 O O m l .
B . 3 8 ( a ) c a H z ( s ) + 2 H 2 o ( 1 ) + c a ( o H ) z ( s ) + 2 H z G )
( b ) 4 . 7 o g
8 . 3 9 ( a ) c a ( s ) + 2 H 2 o ( 1 ) + H ( 9 ) z + c a ( o H ) 2 ( s )
(b) 8.95 9; more than problem 38 because CaH2 alre
has H2 " in i t . "
B . 4 0 ( a ) A l + C g ( s ) + I 2 H 2 o ( 1 ) + 3 c s + ( g ) + 4 A l ( o H ) ¡ ( s )
( b ) 1 . O O l i t e r
B .4 t (a ) Laz (Cz) s + 6HzO(1) -> 3CzHz@) + 2La(OH) ¡ (s )
( b ) 0 . 3 6 1 l i t e r
r l . , t . t . 5 0 6 l i t e r s 8 . 4 3 I . 6 9 4 l i t e r
i l . , t 4 3 9 . 6 ? A 1
l t . , ' ¡ ' i (a ) .125 moles hydrocarbons ; .g125 moles.5OO moles COz; .625 moles water
(b) 2 (hydrocarbon) + 1302 + BCO2 + ]0HzO
(c) 2CaH1s + 1302 -+ BCOz + IOH2O
t . 4 6 ( a ) . 0 1 7 5 m o l e , . O 4 O O m o l e
( b ) . 0 0 2 5 0 m o l e ( c ) C z H r e
I,a!L of Partial pressures
t t - 47 n * ro = . I 94 a tm . , n * , = . 306 a tm .
l l . 48 " " . = . 1875 a tm . , "Nu = . 0625 a tm .
t t . 49 ( " ) " "o = . 25O, Xco , = . 750
(b ) . 350 mo le ( c ) 2 . 4 5 9 C o i
r r - ' ) 0 O . l B B l i t e r B . 5 l O . O 9 1 l
t t . ' i 2 . 7 2 7 a t m 8 . 5 3 . 0 4 6 9
t t . ' ;4 (a) L.379 moles of mixed gases
oxygen;
1 I .559 CO2
liter
4 U l t
(b ) 1 .00- x = moles o f N2Oa remain ing
2x = moles NO2 formed
.621 moles o f N2Oa remain ing . .75g moles o f NO2formed.
( c ) a n d ( d ) . 4 5 0 a t m X " , ^ = . 4 5 O ¡ . 5 5 0 a t m
X * o , = ' 5 5 0 '
¡ ' l " t i c fneory o f
11.55 (a) The actual volume of the moleculessmal1 compared to the voh:ne in whichconfined.
l s
the
negligiblygas is
44 45
(b) Molecules move in straight l ines untiL theycol l ide with other molecules or the walls. A]- lco l l i s ions are e las t i c , i .e . , to ta l k ine t ic energyis conserved.
(c) The kinetic energy of a gas is proport ional tothe absolute temperature and independent of the naof the gas .
(d) Attract ive forces between molecules are negl ig
8.56 Pressure is proportional to the rate at whichmolecules impact on the wal1s. If volume is reby half then there wil l be twj_ce as many moleculesper'unit volume and rate of impacts wil l be doubled¡so the pressure wil l be doubled, as predicted byBoy le 's Law.
Rela t ivenumber o igh Tmolecu le
(b) energ"r
IOOK speed = 279 m sec
5O0K speed = 624 m sec
) l 5B7K
) CO rate = L.25 x COz rate
t 6 . 0
| ( a ) 1 . 1 8 5 I l i r e r - r ( b ) 5 8 . 0
" . 676 g l i t e r -
. 9o2g l i t e r - r
3 0 . 0
I Gases
{ 'b Two main reasons are i (a ) f in i te s ize o f themolecules, and (b) attract ions between molecules.
t, l (a) Hz cl-oser to ideal because i{I is larger and hasgreater intermolecular attract ion.
(b) The gas at IOOoC wil l fol low the ideal gas lawsbetter than at 10OK because the energy of inter_molecular attract ions wil l be much less signif icantcompared to the thermal energy (kinetic energy) acthe higher temperature.
(c) More ideal at I atm. because at lO atm. themolecules are closer and attract ive forces are moreef fec t i ve .
- l
- l
When the temperature is doubled the'average speedof the molecules increases bV ñ. The increased sp,affects the pressure two \^rays; (a) more frequentimpacts, and (b) more momentum transferred perso the overall effect is E x /l = doubling ofpressure, as predicted by Anontonrs law.
8 . 5 7
Charles' Iaw can best be deduced by f irst con-sidering the volume constant. Then a d.oubling oftemperature doubles the pressure (as above) and inorder to restore the original pressure the volumewould have to be doubled (in accordance with Boylellaw) "
Rela t ive lowhigh T
number omolecu le
(a) sPeed
¿ro4 7
(d) The gas with T. = 1O0K is more ideal because the
low cri t ical temperature is an indication of weakln te rmelecu la r fo rces , i .e . , on ly a smal l amount o fthermal energy is required to prevent coalescence ofthe molecules into a l iquid phase.
8 . 6 8 ( a ) . 5 1 4 l i t e r i . O 3 2 L l i t e r
(b ) A t 50 .0 a tm the ac tua l vo lume ( .314) i s IesB tideal (.514) because intermolecular attract ions arethe dominant deviation.
At 80O atm the actual volume (.O42L) i-s greaterthan ideal (.0321) because excluded volume is thedominant deviation.
( c ) A t 5 O a t m , 6 1 1 ; a t B 0 O a t m , L . 3 L 2
8 . 6 9
l r r te rmolecu la r Attract ive Forces
London forces are universaldirect ional and are due toby f luctuations in electron
of on ly . 10-1 s
and completely non-temporary dipoles caused
density on a t ime scaleseconds. Dipole-dipole forces are due
(.I IAPTER 9
t,TQUIDS AND SoLIDS
to permanent dipoles "-,r."á by unlompensated. polarbonds. The negati.ve end ot oie *oi..rrfu attracts thepositive end of the other. Many molecules have nodipole moment and such forces ale absent. UsuallyLondon forces are dominant (see table 9.1, p . 2it6).Expect Clz to have highest Tc
highest "a" vaIue, indicatingattract io¡1.
because i t has the
greatest inlermolec' t .2 (a ) OFz must be bent
so the bond dipolesso the bond dj_poles
(two unshared pairs on O atom)add vec tor ia l l y . BeF2 is s t ra iqh tcancel each other
8 . 7 0 ( a ) 2 2 . 4 1 a t m . ( b ) 2 1 . 9 3 a t m .
(c) The van der Waals equation shows that the pris s l igh t ly less than the idea l .
8 . 7 1 ( a ) 2 . 2 4 1 a t m (b ) 2 .236 a tm
(c) The van der !{aals equation shows that the presis very sl ightly less than ideal; but closerrelat ively than in problem 70, because in problemthe pressure is higher and behavior is less idea1.
8 . 7 2 ( a ) 3 0 . 6 2 a t m . ( b ) 3 0 . 4 8 a t m .
(c) The van der htaals equation shows that the presgis s l igh t ly less than idea1. The d i f fe rence is 0 .4compared Lo 2.L42 in problem 70. At higher tempebehav io r i s c loser to idea1.
He has lower intermolecular forces than H2 as shownby an a value of only .0341 compared Eo .244 for [ I1r
(b) PF3 is a pyramidar- molecule. rf you consider theunshared pair on p to be pointed up\^rard each of thePF bond dipoles has a downward component, which addtogether. BF3 is planar and the btn¿s are at 12Oo so
l l " - : : : " t .anr ( i .e. , rhe vecror ial sum) of rhe rhree
(c) S¡' ,* is distorted tetrahedron with the S atompractical ly on an edge (a1so sometimes carred a ,,sawhorser " a "see-sahr r "
o r "a isp i reno iá r , , doub le wedgedshaped) so that the SF bond áipoles cannor canceleach other. SnF4 is tetrahear-af wit¡, sn at the centerand the resultant dipole moment is ,ero. (Consider
one pair of SnF bonds and observe that i ts resultantmust be equal and opposite to the resu.l-tant of theother two. )
t - J HgC l2 r CuC I2 , BF3 , CHa ¡ pC15 ¡ XeF2 , SFG , XeF ¡ , .
4 The only arrangement
a ? ?
ó . 1 ¿ rboththere
Cl atoms axia1.which has zero
If one or bothdipole moment has
are eguatorial- t o a
( a ) 1 . 7 7 x 1 0 - " m " (b ) . o4772 must be a dipole moment.
A . 1 5 . l 5 B n m
48 4 9
9 . 6
Al I Lrond dipoles cancel in pF5; the axial contr i_but- ions are equal and opposite, and the equatorialare tr igonal planar (as in BF3). pF3 is a tr igonalpyramid with al l bonds contr ibuting, as discussed in9 . 2 b .
Both the N - H and the N - F bonds are polar, butthe negative end of the NF3 molecule is directed awalrfrom the unshared electron pair and is part ial lycancelled by i t . The negative end of NH3 is in thedirect ion of the unshared pair and the molecule dipomoment contains contributions of the same sj-gn fromboth the bond dipoles and the unshared pair.
The case of phosphorus is dif ferent because p ismuch less electronegatj-ve than N. As a result pHbonds are practically non-polar and the dipole momentof PH3 is due only to rhe unshared pair. ;r ' ; ;á;-"-are more polar than NF bonds and make such a largecontr ibution that the counter_effect of the unshiredpair is relat ively tr ivial . The argrment,s can bevisual ized in the f igures below.
').9 As one goes to higher atomic numbers, the atoms (andconsequently the molecules) get larger. Their oucerelectrons are more diffuse and further from thenucleus. Such electrons are more easi ly subject tofluctuations and also more polari-zab1e ly ,r.igfrboringtemporary dipoles. Thus London forces aie greater inthe rarger morecures and the crystals can retain theirstructures to higher temperatures.
') '10 Dipole*dipore forces exist only in those with a d. ipolemoment: CH3C1¡ CH2CL2, and CHC13. Chlorine is a verylarge atom (compared. to the others) ¡ and Londonforces bet\r¡een Cl atoms in neighboring moleculesprobably dominate over other considerations. Thusexpect that the boi l ing points wil l increase in theorder writ ten, with CHa far below the rest.
'l:lls ¡Ilqgoge!_ iond
NHs NFs D H ^
1p
¡ i ¡
,|.
, r 1 l
o I t HFe
9 . 1 3
both these cases the averagie nu¡nber of H bonds per
HF ) NH3 because n' isthan N. Thus the H -and causes the H bond
mol-ecule can be aLunshared pair and
so much more electronegativeF dipole moment is very largeenergy to be very great. In
most l , because NH3 has just IHF has jus t one H.
H bonding can occur both by (1)any H in NH3 joining an unsharedpair on the O atom in H2O, or
H2O joining the unshared pair on the
Any H in NHzOH can join anunshared pair on the O in H2O,
H or eifher H in H2O can join anyof the three unsT-rared paj-rs inNH2OH shown above. ,
t t
z i" , i \ /j\ Despite electronegativi ty considerations, H2Oexceeds the other two because the average number ofH b:nds per molecule can be as high as 2.
9.7 Assu¡ne that the compound.s are al l straight, andisoelectronic except for the S core. Then CS2 l ikeco2 has zero dipore moment because the cs diporesare equal and opposite in direct ion. The o l tom ismore electronegative than S and so the CO bond dipoleis greater than the CS and gives a resul_tant equal tothe dif ference, with the negative end toward O.-
Q" = o, @ rn. r,ewis structure reveat-s formal cwhich act to produce a "dipole', in the oppositedirection to that attributabte to the electro_
can be thought of as being formed by a hydrogen
b o n d b e t w e e n H F a n d F , i . e . , , F , O - - - - H - i ,
but in fact the HF2 ion (bette; writ ten FHF-;is slmmetrical!
o a
( a ) r ¡ - Ñ - nI
H
negativi-ty dif ference. The net sma1l dipole moment ithe result of these contradictory tendencies.
( 2 )
N i n
(b)
either H inN H s .
H
IH - N -
5051
t ' l re Liquid StateThe H on the O in CH3OH (as H*) can join an unsharedpair on the O in H2O¡ or eiH in H2o can join an unsharedpair in the O in CHTOH.
(d) H ¡either H in CH2O can part icL| . . pate. But nonetheless the
H - C = o : so lub i l i t y o f CH2O in H2O isgreatly enhanced by n bondlng
of either H in H2O to an unshared pair on the O inCH2O.
9.L4 One part of the explanation has nothing to do withH-bonding; i t is that the HSO+- salts have much IeEalattice energy to overcome than the SOa= saltsbecause of the smaller anionic charge. H_bondingplays a role also. In both SO+2- and HSOa- the Oatoms can all H bond to the H atoms in H2O, but theHSOa- has the additional advantage that its H arom(which is attached to an O) can H bond. to the O in
H e o .
9 . 1 5 The boiling point data suggest that there is anadditional force of attraction between the unlikemolecules that doesntt exist in either pure l iquid.That additional attraction is an H bond between Cand the O in acetone. The three Clrs pul l enough
'¡. I7 (a) : f the cri t ical temperature is high Lhere muscbe strong attract j .ons, suff icient to cause themolecules to coalesce into a l iquid despite the highkinetic energy associated with high temperature.(b) At the surface a molecule has fewer neighbors thanin the bulk. I f intermolecular attract ions are greac
the molecule has a strong,inducement to move into thebulk phase and increase its number of nej.ghbors,Ieading to a high surface tension. Hign surfacetension means a large tendency to reduce the surface_to-volume rat io, i .e., to minimize the number ofsurface molecules rel_ative to bulk molecules.(c) rf one compares molecules of simirar size andshape, then a high viscosity indicates strongattract ions- Molecules strongly attracted tá eachother will not move easily pasu one another and flowwilL be sluggish. Hor^/ever lh.." are many substanceswith l i t t te intr insic intermolecular attract ionwhich are viscous because the molecules are very longand become entangled (e.g. petroleum tubricantsl.(d) e 1ow vapor pressure indicat.es Iarge inter_
molecular attractions which retard the escapingtendency. A molecule can escape only i f i t has enoughenergy to overcome the attract ions of i ts neighbors.
( c ) HIt . .
H - C - O - H *1 . .
IH
H bonding is of little importance because Cl is notstrong donor, but the O in acetone is. Converselynone of the H atoms in acetone is "H bond active', sOH bonding is of no importance in pure acetone.
9 . L 6 Both molecules have permanent dipole moments andhave similar london forces. H-bonding is present lnboth and because of the 1arge H bond energy it is thrdominant force of attraction in both. The dif
(f) tne higher the boiling point the greater theattract j_ons must be. Boi l ing points vary in theopposi-te way from vapor pressure, i .e., lo", vaporpressure means high boi l ing point. (See part á. ¡
' )- IB The energy a molecule must have to escape from itsneighbors is much greater than the average energy.The Maxwell-Boltzmann curve shows that at any onetime a small fraction of the molecules have sufficientenergly to escape. These are the only ones whichescape, and so the average energy of the remaindermust decrease. I f average energy decreases,temPerature decreases.
electron density from C to render the H atom prone tH bond formation with a strong donor. In pure CHC1¡
lies in that ethylene diamine has t\^/o _NH2 groupsmolecule h¡hich leads to twice as many average H b
(e) Enthalpy of vaporizationintermolecular attractions ;the more endothermi_c is the
is a direct measure ofthe greater the attractionsvaporization process.
per moLecule and thus much more attractive forcebetween molecules.
5 25 3
, ) ] q
f i11in9 i t only part ial ly, the space above wil l
increase the l iquid,s vapor pressure untiL i tthe imposed pressure.
9 . 2 L ( a ) . 0 1 0 a t m : 7 . 1 o C ( b ) . 0 2 5 a t m : 2 L . 3 0 C
Phase Diagrams
a ) ')
1 ? L
1 0 . 0
P/Atn.
1 . 0
'I
. 0 1
An equil ibr ium state is one in which the quanti t ielof substances in equili_brium undergo no change with!1*.: r f a l iquid is placed in a Jrosed container
the l iguid per second, thus maintaÍning the populaconstant.
9.2O The boi l ing point is that temperature at whi_ch the
populated with molecules (of the l iquid substance)the vapor phase- That populat ion remains constantwith t ime as indicated by the constant pressure ofthe vapor, Actual ly the equil ibr ium state is adynami-c condition in which many molecules leave theliquid phase per second and an equal number ofmolecules (not necessari ly the same ones) return tO
vapor pressure is the same as that imposed on thesurface of the l iquid. Vapor pressure is a strongfunction of temperature; i f the pressure on thesurface is increased, raising the temperature wil l
P/Atu¡.
. L 7 5
.100
. 0 0 1 3 r / ' c- o JL 9 9 - L 6 9 - L 5 7 - L 5 2
Solid Xr is denser than l iquid at l .O0 Atm. ThisfoLlows from the posit ive slope of the l iquid-sol idl ine which is "normal. ' , An , 'abnormal" substance l iker^rater is denser in the liquid state and correspondsto a negative slope.
(a) Minus loC. The pressure is ini t ial ly so low thatthe entire sample is vapor. Vfhen the pressure reachesabout .006 atm the sample condenses to sol id ice.Eventual ly at very high pressures (ru100 atm) the icewj- l1 melt as you cross the almost vert j_cal sol id-l iquid l ine.
(b) 5OoC. When the pressure reaches ,r, .12 atm thevapor condenses to a liquid and undergoes no furtherphase change. A t exceed ing ly h igh pressures (> IOTOOOatm) there are dif ferent forms of ice which are stableas h i -gh as 50o and more (no t shown in f ig . 9 .9 ) .
100
1 0
I . U
Estimate the boi l ing points as closely as possibl lfrom the graph; there wil_l be honest dif ferencesbetween observers. Approximate values are: 19o, 6tc82" .
(c) Minuscondensessuperhighice which
5ooc. At tu 4 x 1o-5 atm. the vaporto a solid, which never melts. Ho\,rever atpressures there are other exotic forms ofbecome stable.
3 02 01 0 40T/x
roxf-
- 3' ¡ .25 (a ) t x 10 -
a tm. A t -10oC the sample is a l l vaporand remains so as i t is heated.
(b ) O.5 a tm. A t - lOoc i t i s so l id (o rd inary i ce) andat tuOoC it melts. At about g2oc i t vaporizes andremains vapor.
Note: The pressure scale is non_linear but appT1t: ly logarirhmic in order to-shov¡ afftea tures c1ear lv .
5 455
(c ) 1 .1 a tm. A t - IOoC i t i s o rd inary i ce and a t' r ,0oC ( jus t s l igh t ly less) i t me l ts . A t about lO3oCit vaporizes and remains vapor.
9.26 (a) Minus 60oC. This is between the normal subl ima-tion temperature and the triple polnt so at about 4Atm. the gaseous sample condenses direct ly to sol idCOz¡ and remains so. I t can never become l iquidbecause the sol id-l iquid l ine slopes away in thenormal fashion.
(b) ooc. This is far above the tr iple point but
. below the cri t ical point so at a suff iciently highplessure (n 30 etm. ) the sample condenses to a l iquidand remains so.
9 .27 (a ) 2 a tm. The so l id ( "d ry i ce" ) sub l imes a t about- '72"C and remains gaseous.
(b) 6 atm. This is above the tr iple point so thesol id wil l melt to l iquid COz at about -56oC. Thenat about -53oC the l iquid wil l vaporize and remainvapor.
9.28 Consider the sol id and 1iquid forms of X inequ i l ib r ium: X(s ) i=+ X(1)I f , as i s usua l , the so l id i s denser , then an inc rin pressure wil l favor formation of the sol id (LeChate l ie r ' s p r inc ip le ) . The ske tch on the le f t besho\^/s lhat this will be so only if the slope of themelt ing point l i -ne is posit ive. The oppositesituation, which prevai ls for water, is sketched on+ h a r i ¡ h +
' ) .29 Yes , i ce can be pur i f ied by sub l imat ion in anapparatus in which the pressure is always less thanthe t r ip le po in t p ressure o f about 0 .006 a tms.Likewise the condensj-ng surface would have to bebelow the subl imation temperature for the pressureused. (G iven by the vapor p ressure curve fo r iee- )
' l ' ypes o f Crys ta l l ine So l ids
9 .30 The answercolumns on
9 . 3 1 ( a ) S i , a
( e ) B F 3 ,
( f ) P F 3 ,
e . 3 2 ( a ) o z ,
appears in tab le 9 .4 int h e l e f t .
the f i rs t th ree
( b ) B a , a
netv¡ork crystal , covalent bond.s.
meta l , meta l l i c bonds .
(c ) Fz , mo lecu la r c rys ta l o f non-po la r mo lecu les ,London forces.
(d ) BaFz, j -on ic , e lec t ros ta t i c a t t rac t ions .
9 .33 (a ) BrF has s t ronger Londond ipo le -d ipo le fo rces .
(b) BrCl has stronger Londond.ipole forces, which C12
non-polar, London forces.
po1ar, London and dipole-dico1e.
non-polar, London forces.
non-polar, London forces.
forces as well as stronqer
fo rces p lus d ipo le -I a c k s .
mel t ing ;po la r mo lecu la r .
Br2 wh ich is
( b ) B r z ,
molecular
molecular
molecular
molecular
(c ) BrzO, mo lecu la r non-po la r , London fo rces .
(d ) Ba, meta l , meta l l i c bonds .
(e ) BaBre , ion ic , e lec t ros ta t i c a t t rac t ions .
( f ) BaO, ion ic , e lec t ros ta t i c a t t rac t ions .
(c ) Cssr i s ion ic and most l i ke ly h ighstronger forces than BrCl which is
(d) Cs which is metal l ic, compared tonon-po1ar molecular (London only).
(e) C diamond which requires the breaking of covalentbonds. C12 non-polar mo.lecular requires over-coming only London forces.
565 7
9.34 (a ) s r ; i t requ i res b reak ing meta l l i c bonds whereasC12 requires overcoming only London forces.(b ) SrC lz ; ion ic c rys ta l . S iC la i_s a non_po1ar
mor-ecule requir ing overcoming only r,ondon forces(c) SiBrr+. Both are non_po1ar molecular but SiBramust have greater London forces because bromineis a much bigger atom than chlorine.(d ) SC14. These seem c lose , bu t SC14 is po la r wh i leS iCI r i s no t , so there is the add i t io ia l á ipo fe_d ipo le fo rce .
(e) SiC is a covalent net\,rork sol_id while Siclk ismerely a non_polar molecular sol id bound or.rfy ¡yLondon forces.
9 .35 (a ) f , i . Meta l l i c bonds ; versus H2 on ly(b) L iH. Ion ic c rys ta l r e . l_ec t ros ta t i c
H2 on ly London fo rces .
(c ) L iH. I t i s d i f f i cu l t to choose be tween ion icversus metal l ic crystals. Hoi^/ever LiH wi-th verv
9 . 4 0
9 . 4 I
9 . 4 2
9 . 4 4
O /'1tr
9 . 4 7
M = 5 5 . 7 7for which
M = 4 0 . 1 0
316 pm
N = 6 . 0 2 x
Cube edge
1 2 4 . 5 p m
= 2 . I 7 c m
g mole-r (The element is undoubtedly ironthe accura te a tomi .c we igh t i s 55 .85 . )
g mole- r (p robab ly Ca, M = 40 .08)
9 . 4 3 3 8 9 p m
1 0 2 3 a t o m m o l e - t
London force
forces ; ver
simple
toni-c Crvstals
e . s s ( a )and
( b )
e . 5 6 ( a )and
( b )
e . 5 7 ( a )and
( b )
The zinc sulf idefour ca t ions .
5 4 1 . 6 p m
3 8 4 . 5 p m
594 pm
584 pm
BaO, CaS, NaBr ,
9 . 4 6 I 2 7 . 6 p m
9 . 4 8 3 1 4 p m
9 . 5 0 2 2 2 p m
9 .52 211 pm
1 4 . 9 o ; f o r n = 2 1 0 = 3 0 . 9 "
1 6 . 1 " ; f o r n = 2 , 0 = 3 3 . 8 "sma11 ions, Li- and H , has a large latt ice eneand ranl<s high among ionic .ry=tui" Ín melt ingpoant. Li ranks lGroup r) because "?'.ililnrl:;:t:.ff.ulrllt"lÍthe very 10w dens i ty e lec t ron c l0ud wh ich f i1 lsthe interj-onic space.
(d) Clz. Both are non-polar molecular but C12 hasmuch greater London forces.
(e ) ¡ tC t . I t has grea ter London fo rces , p lus d ipo le_d ipo le fo rces wh ich H2 1acks .
Crystals
9 . 3 6 1 . 4 5 3 g c m 3
9 . 3 7 3 . 5 9 8 g c m 3
o ? o ¡ ¡ _ r .uuu acom. po must c rys ta l l i ze in acub ic la t t i ce .
9 .39 n = 4 a toms. Au must c rys ta l l i ze in a face centeredcub ic La t t i ce .
The cesi.um chloride unit cel l- contai-ns one anionone ca t ion .
4L2 pm (c ) 357 p¡n
The sodium chloride unit cel_l contains four anionsfour ca t ions .
555 pm (c ) 278 pm
9 . 5 8
q ( o
9 . 6 0
9 . 6 1
( a )
( a )
( a )
1 \ I J ,
unit cel l contains four anions
( c ) 1 6 5 . B p m
( b ) 7 . 0 1 s c r n -
t D , / . 5 9 g c m
( b ) 4 : 8 2 s c m 3
AgC1, KC1
5 9
X-Ray _Diffract ion gf Crystals
9 -49
9 . 5 l
o q , a
9 . 5 4
348 pm
7 0 . 8 p m
f o r n = 1 ¡ 0 =
f o r n = 1 r 0 =
5 B
Defect Structures
9.62 Dislocations. Planes of atoms are not perfect lyparal lel. for example where two crystals join; oran extra plane of atoms extends through a portionof a c rys ta l .
point defects arising from deviat ions from perfectstoichiometry. Extra anions or cations may be lodgin interst i t ial si tes, or some latt ice points may bevacant.
Impurity atoms.la t t i ce po in ts ,
9 . 6 3 ( a ) 0 . 5 e " o x y g e n
( c ) 8 . 2 3 9 9 c m - 3
9 . 6 4 ( a ) 5 . 6 4
9 . 6 5 ( a ) 5 8 . 3 9 4
These wil l frequently be found onsubsti tut ing for the proper ions.
vacanc iesr (b ) 8 .244 cm-3
(b) 7% ca t ion vacanc ies
(b) L4e" chloride ion vacancie
r ' I IAPTER 1O
J;OLÜTIONS
' l ' l re So lu t ion Process
The forces of attracLion are less in pure Br2 (1) thanin pure Iz (s), because of the lower atomic nurnber ofBr, corresponding to lower London forces.
lo.2 (a) CH3OH, which can hydrogen-bond to H2O.
(b) NaCl, which separates into ions, each highlyhydrated.
(c ) CH3F, wh ich is more po la r , thus more l i ke H2Owith regard to intermolecular attract ions.
| ( ) . 4
l o . 5
Whether one melts or dissolves 12 the same inter-molecular attract ions must be overcome; furthermorethe interaction of Iz and CCla molecules is sl ightand not very dif ferent from the Iz - 12 interactionin l iquid iodine. However when ionic substancesdissolve in water, very large hydratj_on energies arel iberated to compensate part ly or entirely for theenergy required to melt the crystal.
Smal1 i-ons, highly charged ions.
1a¡ Fe3+, more h igh ly charged. A lso s l igh t ly smal le r ,but this is a minor dif ference.
+( b ) L i ' , m u c h s m a l l e r .
(c ) F , smal le r .
(d ) SN2+, a b i t smal le r .
(e) e13+, because of both smaller size and sreatercharge.
z +( f ) MS
' , much smal le r .
Water usually appears in hydrates as water ofhydration of the positive ion. It may also occupyinterstit ial spaces in the crystal structure.Finally, it may be H-bonded, particularly to anoxyanion.
6 0 6 I
1 0 . 7 First one must consider the enthalpy of solut ion neafsa tura t ion . I f i t i s negat ive , i .e . , the so lu t ionprocess is exothermic, then raising the temperature}owers the solubility in accordance w"ith Le Chateprinciple. By shif t ing back to the left the reactionwill absorb the heat one supplied in attempting toraise the temperature,
L O . B - 4 7 k J m o l e - r
_ - lI U . I - U - / U 5 K J M O J - E
1 0 . 9 - 1 5 k J m o l e - l
This value applies to the combined processes:+ +
N a ' ( S ) + N a ' ( a q )
c r (S) + c1 (aq)
which release energy; as well as the process ofseparating r¡rater molecules from each other toaccommodate the ions, which required energy.
I O . I I - - 7 g 2 k J * o 1 . - l
This value applies to the combined processes:
n¡* (9 ) + nb+ (aq)
F ( g ) + F ( a q )
1 0 . 1 2 . 0 4 8 1 m o l e s , 2 . L 2 9 C O 2
1 0 . 1 3 . 0 0 4 0 9 m o l e s , 0 . 1 8 0 9 N 2 O
ConSentratj-on_of Solutions
IO.14 Temperature-independent measures are: percentagecomposit ion, mole fract ion, and molal i ty. Temperadependent measures are molari ty and normali ty.
1 0 . 1 5 M = > < r n ( 1 - y l 1 0 0 )
1 0 . 1 6 x ( c H 3 o H ) = . 2 9 4 ¡ x ( H z o ) = . 7 0 6
1 0 . 1 7 X ( C e H s o H ) = . 2 L 7 ; X ( C 2 H 5 O H ) = . 7 8 3
1 0 . 1 8 X ( u r e a ) = . 0 3 2 3 I O . 1 9 7 I . 4 %
L O . 2 O 1 3 . 3 e " 1 O . 2 I 7 . 0 1 q K O H
1 0 . 2 2 1 4 . 8 9 K M n O 4 1 0 . 2 3 5 O . 6 9 H B r 3 3 . 7
1 0 . 2 4 ( a ) 5 7 . 6 9 ( b ) 3 3 . 9 m l
I 0 . 2 5 ( a ) 5 . 5 1 M ( b ) 6 . 9 3 m
1 0 . 2 6 ( a ) 3 . t 7 6 M ( b ) 3 . 6 0 m
t . o . 2 7 3 . 3 5 M t o . 2 8 0 . 7 8 9 M
| o . 2 9 2 5 . 5 m l 1 0 . 3 0 B . l t m l
1 0 . 3 1 0 . 3 1 6 M 1 0 . 3 2 O . 4 O O M
1 0 . 3 3 X s o l u t e = . 0 8 4 3 , X s o l v e n t = . 9 1 5 7
1 0 . 3 4 ( a ) 2 N a 2 0 2 ( s ) + 2 H z o ( I ) + 4 N a o H ( a q ) + 0 2 ( 9 )
( b ) . 0 7 3 3 M
Pressure Boi 1i Po in t o f So lu t ions
.265 Atmos.
.171 Atmos.
_ - lt Q . ¿ q m o l e
( a ) P _ = 1 . 1 1 7 A t m o s .A
c . 1 A
0 . 8 8 6
- t
Y¿-¿ g moJ -e
1 0 . 3 6
r - u . 5 t
1 0 . 4 0
( b ) . 8 3 8
t t ) . 4 2 ( a ) . 4 3 4 A t m o s .
(b ) Ac tua l p ressure ( .400) i s less than idea l ( .434) .Negative deviat ion from Raoultrs Law.
(c) Heat must,be evolved when the l iquids are mixedsince intermolecular forces are greater than in thepure l iquids.
(d) Since the vapor pressure is lowered a highertemperature is required to boi l and so, i f anazeotrope is formed, j_t must be a maximum boil ingazeotrope.
6 2
10 .43 (a ) . 497 Aünos .
(b) Vapor pressure shows a very strong positivedeviation from Raoultrs Law.
(c) Heat must be absorbed upon preparing the solutionsince there is less force of attract i-on betweenmolecules in the mixture than in the pure liquids.
(d) Mixtures boi l relat ively easi ly. These two could,form a minimum boilinq azeotrope.
1 0 . 6 5 T = 2 7 . 1 A t m o s .
A pressure o f 27 . f A tmos. on the sa l t water wou ldjust maintain equi l ibr ium in the rate of f low of hraterbetween one side of the membrane and the other.
_Addit ional pressure would be necessary to favor theflow from the salt side to the fresh side, the rateof f low increasing with increasing added pressure.
sglut-isJnq o-f_ Electrolytes
10.66 i = 3 ions per mo lecu le
1 0 . 6 7 í = 2 . 6 7
1 0 . 6 8 t f = - ¡ . 4 0 o C
1 . O . 6 9 t f = - . 2 4 2 " C
1 0 . 7 0 % i o n i z a t i o n = 3 . 5 %
LO.44
1 0 . 4 5
LO"47
1 0 . 4 9
1 0 . 5 1
ro .52
(a) 9og mole- l
3 3 3 9
- 1 . 7 5 " c
L22.59 mole-r
(b) .611 Atmos.
1 0 . 4 6 1 4 . 8 9
10.48 -11.8%C,/m
l - 0 . 5 0 I 5 4 . 3 9 m o l e - l
1 0 . 5 4 2 7 . 0 g
10 .56 62 .A g mo le I
10 .58 186 9 mo le - l
1 0 . 6 0 3 3 . 6 9
Ii i i iO.62 334 g mole-l
(b) 109 mm
J-75.69/moIe round off to 176
1a) PUz = .800 Atmosr nO, .200 Atmos.
( b ) x w z = L . 4 8 7 x l o - s , * o . O . 7 g 7 x l o - s
( c ) - . 0 0 2 3 6 o C
1 0 . 5 3 2 . 7 7 e " C / m
1 0 . 5 5 1 6 1 . 1 4 C
1 0 . 5 7 6 9 . g g m o l e - '
Osmotic Pressure
10 .59 2 .9 I A tmos .
10 .6 I 67 ,OOOI mo le -1
10 .63 (a ) . 01055 A tmos .
L0.64 1BO g mole- l
64 65
( l t^ t , , t ' i lR f f
REACTIONS IN AQUEOUS SOLUTION
l letathesis Reactions
1 1 . 1 ( a ) z n s ( s ) + 2 H - + H z S 1 g ) + z n 2 +
( b ) s r 2 + + c o 3 2 + s r c o 3 ( s )
(c) l¡o reacti-on
(d) ¡¿g2* + 2OH + Mg (oH) 2 (s )
( e ) p o , * t - * 3 H * + H ¡ p o +
L . 2 ( a ) e c - + I - ' A 9 I ( s )
( b ) s o s 2 * + 2 H + + H z o + s o z ( g )
(c ) No reac t ion
( d ) s r 2 + + 2 o H + N i 2 + + s o ¿ + 2 - * s r s o + ( s ) + N i ( o H ) z ( s )- +
( e ) O H + H ' + H z O
1 .3 ( . ) pbz+ * H2s (g ) + pbs 1s ¡ + 2H+(b ) ga2+ + s2 * zn ' * + soa2 - - * Baso+ ( s ) + zns ( s )(c) ¡ ¡o react ion
(d) Hgzcoals) + 2u- + 2cr -> Hg2cr2(s) + H2o + coz (g)(e ) Fe (oH) g ( s ) + H3pO4 + Fepo+ ( s ) + 3H2o
L.4 (a) 2NHa+ + So4' - * ¿u '* + 2oH -> caso,+ (s) + 2Hzo
+ 2NHs (g)
(b) No reaction) + a -
( c ) C d - ' + S - - + C d S ( s )
( d ) F e z ( c o s ) s ( s ) + 6 H + + 2 F e 3 t + 3 c o 2 ( 9 ) + 3 H 2 o(e) pb2+ + so42 + pbso,+ (s )
Oxidat-En-Reduc ti o-n Reac tio_n s
11.10 (a ) zn is ox id ized f rom 0 to 2+ ; Zn is the reduc ingagent r C12 is reduced f rom O to l - ; C12 is then v i ¡ l i o i - n .rgenc .
(b ) ReCls i s reduced, Re goes f rom 5+ to 4+; ReCl5is the ox id iz ing agent . SbC13 is ox id ized . Sb goesf rom 3+ to 5+; SbC13 is the reduc ing agent .
(c) Mg is oxidized from 0 to 2+; Mg is the reducingagent . CuC12 is reduced, Cu goes f rom 2+ to 0 ,CuCl2 is the ox id iz ing agent .
(d ) No is ox id ized , N goes f rom 2*reducing agent. O is reduced fromox id iz i -ng agent .
(e ) I {O3 is reduced; W goes f rom 6+ox id iz ing agent . H2 is ox id ized ,I + ^ i q J - L r o r a ¡ l r r ¡ i ¡ ¡ . . J agenr . .
Oxidation Numbers
1 1 . 5 C l 0 3
c l 0
C1O'+2 -
CrOa2 -
soe
1 1 , 6 ( a ) 6 + ,
( s ) 3 * ,
1 1 . 7 ( a ) 2 * t
( s ) 5 * .
I 1 . B ( a ) 3 * ,
( s ) 3 t ,
1 1 . 9 ( a ) 5 * ,
(s) 5* ,
C I 3 + ; O H N 1 f ;
I \Tq+. \T^^ \ r :L ' v ¿ , " 3 + ;
Mn7+ ; COs- C4+¡2-
cr6+; so,* 2-
s6+;
As5+ ; po , * 3 - p5+ .
( d ) 1 + , ( e ) 4 + , ( f ) 2 - ,
c15+;r . l 1 r .
CI1+¡
54+;
( b ) 6 + ,
(h) 5+
(b ) r - ,( h ) 6 +
(b) 3 f ,
( h ) 5 +
( b ) 6 + ,
( h ) 6 + ,
Cl0z
Nos
MnOa
Cr zoz3 -
AsOa
( c ) 5 * ,
( c ) 6 + ,
( c ) 4 + ,
/ A l a ¿
( d ) 5 + ,
( c )
t i I
4 * , ( d ) 6 + ,
6 +
( e ) 5 * , ( f ) 6 + ,
( e ) 4 + , ( f ) 5 + ,
( e ) 6 + , ( f ) 6 + ,
Eo 4+¡ NO is theO to 2 - ; 02 is the
to 0 ; WO3 is theH goes f rom 0 to l+ t
6 66 7
I t . l I (a ) C lz i s reduced f rom O to 1_ ; C l2 i s the ox i -d iz ingagent. NaBr is oxidized, Br goes from _l to O, NaBris the reducing agent.
(b ) Zn is ox id ized f rom O to 2+; Zn is the reduc ingagent . HCI i s reduced, H qoes f rom 1+ to 0 ; HCI i sthe oxidizing agent.
(c ) Fe2O3 is reduced, Fe goes f rom 3+ to 0 ; Fe2O3 isthe oxidizing agent. A1 is oxidized from O to 3+iA1 is the reduci_ng agent.
(d ) OF2 is reduced, O goes f rom 2+ox id iz ing agent . H2O is ox id ized ,0 ; Hzo is the reduc ing agent .
(e) HgO is both oxidized and reduced and is bothreducing agent and oxidizing agent. The Hq isreduced from 2-r to 0 while the O is oxidizád from2- to O. The reac t ion is usua l ly ca l led a"decompos i t j_on"
ra ther than, ,ox j -da t ion_reduc t ionr , ,wh ich i t i s techn i -ca l1y .
I . I2 (a ) 2H2O + 4MnOa + 3C102 -+ 4MnOz + 3C10u + 40H(b) BH+ * Cr2o72 + 3H2s + 2cr3 t + 3s + 7H2o(c) 6H2O + p4 + IOHOC1 + 4H3pOa + 10Cf + lOH+(d) 3cu + 8H- + 2No3 * 3cu2f + 2NO + 4H20(e) PbOz + 4Hf + pblz + 12 + 2H2O
1.13 (a ) 4sb + 4H+ + 4No3 + Sbao5 + 4No + 2H2o
(b) Bnar + 5H2Soa + HzS + Atz + 4Na2SO4 + 4H2O( c ) 2 I O s + 4 H 2 O + 5 S O z + I z * 5 S O a 2 - + B H +(d) 2NF3 + 3A1C13 + Nz r 3Cl2 + 2A1F3
(e) AsaO5 + 4CI2 + IOH2O -+ 4H3Asóa + BHCI
L . L 4 ( a ) 6 F e 2 + + 6 H + + c r o 3 + 6 F e 3 r + c l _ + 3 H 2 o(b) 3p t r 16H- + 4No3 + lBCl + 3p tC1s2- + 4No + 8H2O(c) cu + 4H+ + soa2- + g r r2+ + so2 + 2H2o
(d) p¡ + pbo2 + 4H+ + 2Soa2 + 2pbSo+ + 2H2o(e) MnO2 + 4HI + MnI2 + 12 + 2H2O
(a) 24Ag- * 4AsH3 + 6H2o -> 24Ag + As4o5 + 24H+
(b) 2Mn2+ + 5Bio3- + 14H+ + 2Mno4 + 5Bi3+ + 7H2o(c) 2NO + 4No3 + 4H-r + 3N2O4 + 2H2Q
(d) 2MNOa f 11H+ + 5HCN + 5I -> 2Mn2* + BH2o + 5ICN(e) 3zn + l-2H+ + 2:H2Mooa -> 3zn2t + 2Mo3+ + BH2o
( a ) 2 H + + 2 r o 3 + 4 c l + S 2 o 3 2 - + 2 s o + , - * 2 r c l , + H 2 o(b) 3Se + 2BrO3 + 3H2O + 3H2SeO3 + 2Br
(c ) 5H3ASO3 + 2MnOa + 6H+ + 5H3AsOa + 2Mn2+ + 3HeO(d) Hsroo + 7r + 7H+ + 6H2o + 4r .2
(e) 12n+ + 3pb3oa + 6Heo - r 6pb2+ + 3pbo2
(a) e r - + C103 + 6H+ -> 3rz + c l + 3H2o
(b) 4zn + No3 + loH+ -> 4zn2* + NH++ + 3H2o
( c ) 3 H 3 A s O 3 f B r O 3 + 3 H 3 A s O a + B r
(d) 2H2SeO3 + H2S + H* + 2¡zo + 2Se + HSoa
(e) 4HzO + 2ReO2 + 3Clz - ) 6C l_ + 2HReO¡ + 6H+
(a) 6Fe2+ + c r2o72 + l4H+ + 6Fe3t + 7H2o + 2cr3+(b) 5HNO2 + 2MnOa + H* + 3H20 + 5NO3 + 2Mn2+
(c) 3As2S3 + 5C- r -O¡ + 9H2O + 6HgAsO,+ + 95 + 5C1
( d ) 2 I O 3 * 3 N 2 H a + 6 H e O + 2 I + 3 N 2
(e) 3cu + 2Nog + BH+ - 3cu2* + 2No + 4H2o
(a) p , * + IOHOC1 + 6H2O -> lOH+ + lOC1 + 4H3pOa
( b ) x e o 3 + 6 H r + 9 r + x e + 3 H 2 O + 3 I 3
(c ) 3uo2+ + c r2o72 + BH+ * 3uoz2+ + 2cr3r + 4H2o
(d) BrO3 + 3 !2C2Oa -> Br + 6COz + 3H2O
(e) 4NO3 + 3Te + 4H+ + 2lzo + 4NO + 3TeO2
( a ) 2 4 H - + 3 4 r + H 9 s ( r o e ) z + s H g r { ' - * B r , + L 2 H 2 o
(b) Mnoa + BH+ + 4Mn2+ + I5 l2p2oz2- + 5MnHzpeoz3-
+ 4H2O
( c ) 3 C s ( N H 2 ) 2 + 4 e r o ] + 3 H 2 O ' - > 3 C O ( N H z ) z + 3 S O a 2
+ 6H- + 4Br
to 0 ; OFz is theO goes from 2- to
1 1 . 1 5
I l - . 1 6
1 1 . 1 7
1 1 . 1 8
1 1 . I 9
L J - . ¿ U
6 9
( d ) 2 r J H * * 5 c o ( N o 2 ) . t - * l l M n o f + L 4 H 2 o + 5 c o 2 +
+ 3ONO3 + 11Mn2+(e) z¡t+ + 2cNS + 3ro3 + 6c1 + Heo _F 2cN + 2soa2
+ 3 I C 1 2
( f ) 26H2o * 2Cr r3 + 2 lCI2 _> 2CrO+t - * 610r - + 52H+
+ 4 2 C I
I I .2 I (a ) BOH + 52- + 4 I2 -> Br + So, *2- + 4H2O(b) H2O + 3CN * 2MnOa -+ 3CNO + 2MnO2 + 2OH(c) 4eu + BCN * 02 + 2H2O -> 4Au (CN) 2 + 4OH( d ) S i + 2 O H + H 2 o + S i O g 2 - + 2 H 2(e) 2cr (oH) g + 4oH + 3Bro + 5Hzo + 2croar- * 3Br-
1 7 . 2 2 ( a ) 2 0 H + 2 A I + 6 H 2 O + 2 A 1 ( O H ) 4 + 3 H 2(b) zo¡ l - + s2o3 2-
+ A}CI - + Hzo + 2soa 2-
+ Ac I - �( c ) I z + j C I z + I B O H + 2 H 3 I O 5 2 - + 6 H 2 O + 1 4 C 1( d ) 2 B i ( o H ) 3 + 3 s n ( o H ) + 2 - * 2 B i + 3 s n ( o H ) 6 2 -(e) 3NiO2 + 2Fe + 6H2O -f 3Ni (OH) 2 + 2Fe (OH) 3
1 1 . 2 3 ( a ) 5 H c t O 2 + o H + 3 H z o + 4 C I o 2 + c I( b ) B M n O , + + B O H + I + B M n O a 2 - + I O a + 4 H 2 O(c) p+ + 2H2o + 4oH + 2pH3 + 2 lpo32( d ) s b H 3 + o H + 3 H 2 O _ + S b ( O H ) a + 3 H 2( e ) C O ( l l H r ¡ , + 3 O B r * C o z + N z + 3 B r + 2 H 2 o
LL.24 (a ) 4 ¡ ln (OH) 2 + 2H2O + Oz + 4Mn (OH) s(b) 3c1z + 6OH - ' 5c I r - c lo3 + 3H2o(c) 2HXeO,+ + 2OH + Xe + XeO6a- + 02 + 2H2O
Note: There is no unique ans\¡¡er to this problem; i tdepends on an arb i t ra ry cho j -ce o f the 02 to Xe ra t ios .For ins tancef another answer i s :
4oH + SHXeoa + 6H2o + 66 ,z + 3Xeo5+- + 5X"( d ) 2 a s + 6 o H + 2 A s o 3 3 - + 3 H ,
(e) 4on- + 2s2oaz ¡ oz + 4so32- + 2H2o
1 1 . 2 5 ( a ) g a t + 3 N O 3 + 5 O H + 1 B H 2 O - + B A 1 ( o H ) , *
(b ) 6oH + 2Nj -2+ * Br2 + 2NiO(OH) + 2H2O +
( c ) 3 5 + 6 O H - + s o s z - + 2 s 2 - + 3 H 2 o
( d ) 1 O 0 H + 4 I 2 + S 2 o 3 2 + 2 S o 4 ' - * B I - *
(e ) s2- + 4Ho2 -+ 4oH + so42
LI .26 (a) p¡S + 4H2O2 -> AHzO + pbSOr+
(b) 2Cr (oH) 3 + 3H2O2 + 4OH - t 2CrOq
(c) 2MnOa + 5H2o2 + 6H+ -> 2j/rn2t + 5o2
(d) Ag2O + H2O2 -> 2Ag + 02 + H2O
+ ?I\TH ̂
2F,r
5 H 2 O
B H 2 O
+ B H 2 O
/ \c ids and Bases ; A Bas ic Ox ides
1. I .27 Hydron ium is usua l ly cons idered to be H3O+, thoughin fact more water molecul-es on the average areassoc ia ted w i th i t . T t i s imposs ib le fo r H* to ex is tindependently since there are no core electrons, andso the f ie ld a round the t iny p ro ton is so in tensethat the H+ wil l st ick to anything near i t .
I I t A M ^ h ^ ^ r ^ + ; -I L . z e l r u r r u ¡ r r u u r c á c i d : H N O 3 , H C l
P o l y p r o t i c a c i d : H 2 S O a ¡ H 3 p O 4
Normal sal-t ;
Ac id sa l - t :
N a 2 S O a , K C 1
NaHSOa ¡ KHC2O4
1L.29 (a ) HwO3 + NaOH -+ NaNOs + H2O
( b ) 2 H N o 3 + M g ( o H ) z + M g ( N o s r z
(c ) 3HNO3 + A1 (oH) 3 -> A1 (NOs) e
1 1 . 3 0 ( a ) K O H + H B r - > K B r + H 2 O
(b) 2KOH + H2SOa + KzSO+ + 2H2O
( c ) : X O H + H 3 p O 4 + K ¡ p O + + 3 H 2 O
I 1 . . 3 1 ( a ) 3 N a O H + H 3 P O a + N a 3 p O 4 + 3 H 2 O
(b) 2NaOH + H3pOa + NazHpO+ + 2H2O
( c ) NaOH + H3POq + NaHzpO¡+ + H2O
+
+
2 H 2 O
3 H z O
7 077
I I , l ; l ( ¡ ) b rom ic ac i d (b) potassium bromate
(c) hydrobromic acid (d) sodium nitr i te
( t , ) po tass ium hydrogen su l fa te
(f) potassium sulf i te (g) sodium hydrogen carbonate
(h) sodium dihydrogen phosphate
( i ) copper ( I I )n i t ra te
1 1 , 3 3 ( a ) H C l o a ( b ) H r
(d ) H ro3
( f ) ca (HCo3 ) 2(S) Cu (woz ) z
IL .34 (a ) H2O + C12O -> 2HCLO
(b) H2O + N2O5 + 2HNO3
( c ) S O g f H 2 O + H 2 S O 4
( d ) C O z * H 2 O + H z C O ¡
(e) CaO + H2O + Ca (OH) z
( f ) Na2O * H2o + 2NaOH
( g ) P + O r s + 6 H 2 O + 4 H 3 p O a
I l . 3 5 ( a ) C I z O z , ( b ) N 2 O ¡ , ( c ) s o z , ( d ) B 2 O 3 ¡ ( e ) A l e O g
( f ) z n o , ( S ) K z o
1 1 . 3 6 ( a ) C a ( O U ) z + C O 2 + C a C O 3 + H 2 O
(b) COz + 2OH + HzO + CO32
(c) znO + 2H+ + Hzo * , I - ' *
(d) BaO + SO2 + BaSO3
(e) FeO + 2HC1 + FeClz + H2O
11.37 An amphoteric oxide can be dissolved by either acido r b a s e . z n o i n a c i d ( s e e 1 1 . 3 6 c )
z r r o + 2 H + * H 2 o + z n 2 +
Upon treatment wi_th base:
ZrrQ + H2O i 2OH -> Zn(OH) a2
Uquivalent Weights_and Normal Solutj-ons
L I . 4 9 ( a ) L / a , ( b ) L / 6 , ( c ) I / 5 , ( d ) L / 6 ,
( c ) H I O
(e ) NaHSOs
Volumetric Analysis
t - 1 . 3 B 0 . 3 B 5 B M
l - 1 . 4 0 4 L . 2 B e " M g ( o H ) 2
I I . 4 2 6 9 . 6 2
L L . 4 4 ( a ) . O 4 4 7 5 9 N a C l
1 1 . 4 5 ( a ) M n O a + B H - +
1 1 . 3 9 0 . 0 3 0 5 4 M
1 1 . 4 1 7 2 . 5 % H 2 C 2 O 4
1 1 . 4 3 . 1 1 0 1 M N a o H
( b ) . B 9 s %
t L a + o +
5 F e - ' + 5 F e " ' + M n - ' + 4 H 2 O
- + 3 N z + 6 H 2 O + 2 B r r
- u --> 2 f + S tOe
-
( e ) I / 2 ,
I T . 4 6
r1, .47
t l _ . 4 8
( b ) 2 O . 0 % F e
(a) 3NzH+ + 2BrO3
( b ) 2 4 . 0 % N z H 4
. 3 4 1 % F e
(a) 12 * 2S2Os2
( b ) . L 5 B 6 g t z
( f ) L / 4
t 1 . 5 0 H C l 6 . 0 0 N ¡ H 2 S O a
l . I . 5 f H C l 6 . 0 0 M ¡ H 2 S O q
L L . 5 2 5 7 . 0 m l H z S O ' +
1 1 . 5 4 . 4 6 5 N b a s e
1 . 1 . 5 5 ( a ) 9 0 . 0 9 e q u i v .
I t - 5 6 ( a ) 6 4 . 0 g e q u i v .
t L . 5 7 ( a ) . 1 2 0 0 N
( c ) . 0 1 s 0 M
r . t . 5 8 5 7 . 8 6 % F e
l 2 . 0 O N ' H 3 P O ' + 1 B . O O N
3 . 0 0 M ' H 3 P O a 2 . 0 0 M : '
1 1 . 5 3 . 4 0 9 N a c i d
-1 (b) 1 acidic H/molecule
-l (b) 3 acidic H,/molecule
( b ) . 0 7 5 0 N
7 3
CIIAI"]'ER 12
CHEMICAI KINETICS
t2 . ' l
Energy 4
t ra , r
4
AH
L _
eactan ts
l : l .B Rates are proport ional to the concentrat ions of the
reactants to the po\¡¡er of their coeff icients only i f
the reaction occurs in a single step. Most overal l
reactions represent the sum of several consecutiveqtcns (the 'rmechanism"). Note lhat single step
reactions usually involve only t\^¡o moleculest
occasional ly three, white most balanced reactions
.involve many molecules.
t:1.9 Most col l is ions are ineffect ive because the col l ision
energy ( (Ear f , i .e - r too smal l to "damaqe" the
col l j .ding molecules. Even i f the energy is great
enough the molecules may not be properly orienLed with
respec t to each o ther to reac t r i -e . , key a toms and
bonds are in the wrong Places.
l . l .10 Usually i f a thermodynamical ly feasible reaction does
noc succeed, i t is because i t is much slower than
competing side reactions. In this case the decompo-
sition of perbromate to bromate and oxygen could be
the trouble' or the very rapid oxidation by perbromate
of other species present. By the same token'
perbromates probably are very fast oxidizing agents'
1, , , ,¿
Ll-I l (a) The activated complex contains both reactants in
a single species' enriched by the energy Ea,f, and in
a configurat,ion that can easily revert to either the
reactants or to the Produqts.
- - r_
tIE a , x
- l
(b ) . O4o sec - l
Reaction Rates, Rate Equations
L 2 . t (a) rate = k tNol 2
[H2 ]
(b ) k un i ts a re M-2 se" - l
Note: M, molari ty, symbolizes the
( c ) r a t e = k ' [ N o ] 2 [ H z ] , h " r e k r =
L2.2 (a) Rate of form. of C = ktAl tB l(b ) k = 1 .56 x 1o -2 M- l sec
I
L 2 . 3 ( a ) R a t e o f f o r m . o f C = k l B I 2
( b ) k = . 0 3 3 M - r r . " - t
I2 .4 (a ) Zero order , k un i ts a re M sec- l
Rate = . lOQ M sec r
(b ) F i rs t o rder , k must be in un i ts o f sec- l
Rate o f d isapp. = .0050 M sec- l
(c) Second order, k must be in units of M-l sec
Rate o f d isapp. = 2 .5 x lO 4
M sec- l
1 2 . 5 ( a ) . O O B O M s e c - r
( c ) . 2 o o M - l s e c - r
12.6 (a ) Rate(a) rz ln i t ia l Rate = . l8B
(b) Rate = practical ly zero
(Actual ly [NO] must approach zero asymtotical ly)(c ) Rate(c ) rz ln i t ia l Rate = .074
(d) na te(d) rz rn i t ia l Rate = 4 t imes
(e) Rate(e) ,z In i t ia l Rate = B t imes
un i ts mo le l i te r - l
2k
74 7 5
(b) Earf is the minimun energy necessary to raise thereactants into the activated complex configuration,or the minimum energy of collision which can resultin product formation.
(c) The reaction order ís the sum of the dependenciesof rate upon concentration, i.e., the sum of theexponent,s of concentrations in the rate equation.
(d) A catalyst changes the reaction rate, usuallyspeeding it up greatly, though very little catalystmay be required and it is not consumed in thereaction.
(e) Chemisorption is the process in which moleculesstick to a surface with considerable energy,comparable to chemical bond energies- Chemisorbedspecies are usually very reactive.
(f) The rate determining step is the one step in amechanisÍi that goes so slow1y that its rate isessentially the reaction rate.
(g) A reaction intermediate is a species which isquite unstable $¡ith respect to further reaction.It exisüs in small concentration during the courseof a reaction in which it is being formed and reactedh'ith rapidly.
(h) A zero-order reaction proceeds at a rateindependent of the concentrations of the reactants.
- k2 [No2]k1 [N2os] +- k ths [No] [Nzgs] - - k-2 [No2]kr [N2os]-
kz [Noz] + kg [No]
- krk g [Nzos ] [N-o] -- kz lNoz l + kg [No ]
12.L4 Rate of dÍsappearance of A = rate of appearance of
products
= ( k r kg / kz ) [A ]
12 .15 Ra te o f change o f [ o ] = o = k r l oe l - kz [o2 ] [ o ]
- k g [ o e ] [ o ]
Uropping the k3 term, kr [Os] = kz [Oz] [O)
t o l = ( k r l k z ) I o g l / [ o z ]
Ra te o f d i sapp . o f 03 = k r [ o ¡ ] - kz [ oz ] [ o ] + kg [ os ] [ o ] '
But as stated earlier the first tvto terms above
balance out to zero and rate = ks [og] [o] I
r a te = ks [ oe ] $ t / kz ) l og l / l oz l
= ( l ¡ ¡ k3 , / k2 ) l ogJ2 / l oz ] = k [og ] ' / l o r j
I : r . 1 6
L2.L2 ICI + H2 + HI + HCl s low
ICl + HI + HCl + Ie fast
Net overall reaction is the sum of the above.cancels out; i t is the unstable intermediate.
H I
L2.L3 Rate o f change o f [NO¡ ] .
' k2 [No2] [No3]
= O = k r [ N z O s ]
- ks [No] [Noe]
+ kg [No] )
Ener
kr [NzOs] = [ r ¡Os] (kz [NOz]
I rñ^ = k r [NzOs]kz [Noz ] + k3 [No]
Rate of disapp. o f Nzos = k r [N2o5 ] - kz [Noz ] [Nos ]
_ kz [Noe ] k r INzos ]kz [Noz] + k3 [No]
- T - -
Er=1-0
eacEanEs
= k 1 [ N 2 O 5 ]
76
12.17 Rate o f change o f [No3] = O = k l [NO] toz l - kz lNos j
- k g [ N o s ] [ N o ]
Many substancesi ca11ed "negative catalysts¡ ' arerea l l y inh ib i to rs o r re ta rders , i .e . , they reac t w i thand remove intermediates. But retarders and inhibitorsare consumed i-n the reaction. One can conceive of atrue negative catalyst in a mult istep reaction, i f thecatalyst enhances the formation of an intermediate not.othen^/ise present in the mechanism which is kinetical lys tab le ( i .e . , separa ted by a la rge energy bar r ie r f romthe f ina l p roduc t ) .
I2.2O A homogeneous catalyst is present in the same phaseas the reactants and is regenerated in that phase asproducts are formed. A heterogeneous catalyst is aseparate phase, such as a sol id catalyst for gasreactions. The surface attracts one of the gaseousreactants and holds i t in pl-ace unti l the other gaseousreactant can contact i t . In addit i-on to faci l i tat ingcontact between reactants the catalyst, in cases ofchemisorption, wi l l act j-vate the adsorbed species.
Rate EquatÍons an-d_ Temperature
Neg lec t ing the k3 te rm: k r tNOl [Oz]
[No3] = (k t /kz )
Propagation Cl
cHs
Terminations 2Cl_
Ener
Uncata lyzed Path
CataLyzed Path(usual ly moreconp l ica ted)
= kz [Nos ]
tNol [o2]
= ( k r ks / kz )Rate o f fo rm. o f NO2 = ks tNO: l [NO]
tNol 2
[o2 ]
The above ís f irst order in 02 and second order in NOas requ i red .
12 . lB In i t ia t ion C l -z -> 2CI
+ CH+ + HC1 + CHs
+ C lz + CHsCl + C l
+ C f z i 2 C H 3 + C e H e ;
+ C l + C H 3 C I
L 2 . L 9
L 2 . 2 I 2 6 7
L 2 - 2 3 2 4 8
L 2 . 2 5 3 . O
1 2 - 2 7 2 . 9
12 .29 178
- l
KLI MOIC
- t
kJ mole -
- t - l
M - s e c -
- t
- tmole
-
1 2 . 2 2 1 3 9 . 3 k J m o l e - l
L 2 . 2 4 7 . g x 1 o s M - l s e c - 1
- 3 - 1 - lL 2 . 2 6 4 . 7 x 1 0 - M s e c
L 2 . 2 8 6 6 B K
L 2 . 3 0 5 2 . 3 k J m o l e I
M
KLJI
Ail_ * _
eac é r t L >
A catalyst provides a path with a lower Ea,¡ so that
a much larger fract ion of col l is ions are effect iveand the rate is thereby increased. As shown AH isunaffected by the height of the barrier since weobtain the same products at the same energy leve1 bye i ther pa th . Both E_r , and " . r , . ru decreased by tñe
same amount of energy by the catalyst, so that bothrates are increased by the same factor.
7B79
CHAPTER 13
CHEMICAL EQUILIBRTUM
(s)( h )
( i )
L 3 . 7 ( a )
( e )
( i )
n independent of P, depends only on Tt no change.
Catalysts affect ratesf not Kt no change.
Addit ion of A affects the equil ibr ium concen-
t ra t ions bu t no t K (see (g ) above) ; no change.
r i g h t , ( b ) 1 e f t , ( c ) I e f t , ( d ) n o e f f e c t ,
r igh t , ( f ) no changer (g ) no change, (h ) r igh t ,
r ight
Chemical Equit ibr ium, LeChat-el ier ' q Principle
1 3 . 1 ( a ) K = [ c o ] 2 Í o z l / l c o z J z
L ) . ¿
1 3 . 5
1 3 . 6
( b ) K = [ o 2 ]
( c ) K = [ o z ]
( d ) r = l c s z ] [ H z ] u / l ¡ ¡ " s J t l c r ¡ u l
( e ) r = t c q z / L c o 2 l
(a ) le f t , towards less moles o f gas
( b ) l e f t , ( c ) l e f t ' ( d ) l e f t , ( e ) l e f t
endolhermic 13.4 exothermic
(a) K must decrease
(b) K, and Kp are dependent on temperature only and
do not change \^/ith pressure.
(a) [cJ must decrease
(b) [C] wi l l increase to a greater extent than
expected for an inert mixture of gas.
(c) Adding A at constant volume drives the reaction
to the r ight so that [C] increases. However i f
A is added at constant pressure [CJ would be
decreased by the di lut ion, but to a less extent
than expected for an inert mixture of gas.
(d) Catalyst affects only rates, no effecl on
equi librium concentrations .
(e) Removal of B at constant volume drives the
reaction to the left so that [C] decreases. But
at constant pressure the removal of B wil l
concentrate C in a smaller volume and [C] will
increaser but not as much as expected for an
inert mixture.
( f ) K decreases
Proplems Basgg o-n Equilibriun llonstants
r3.b 61.0 l r3.e) .0942 a1- jm2) \--_,--l
1 3 . 1 0 ( a ) I C I 2 ] = . 0 5 0 M ' I P c 1 s ] = . 0 6 0 M
(b) .042 mole l i ter - l
( a ) [ so2 ] = . 0040 , [ oz ] a t eq - = . 0036
(b) 278 (mole/ l i ter ) I
- f ¡ - t
7.6 x 10 mole l i ter -
- ( - t
B-2 x 10 '
mole l i ter -
- 4 - l5.47 x Lo mole t i ter
-
.0684 mole l i ter
t - 3 .11_
L3 .T2
l - J . l _ J
1 3 . l _ 4
I 3 . I 5
1 3 . 1 6
r 3 . 1 7
lHz l = [ I z ] = . 319 mo les l i t e r
I n r l = 2 .362 mores f i t e r - r
(a ) [Hz ] = l t z l = I . 35 x I o -3
(b) .0127 moles l i ter - r
- 1
mol.es l r fer
( c ) 2 1 . 3 %
13.18 .0253 mo] .e l i te r I
1 3 . 1 9 . O 3 O O m o l e l i t e r l
BO B1
t ^
(a ) [Hzo ] = [ co1 = . 0335 M, [Co2 ] = [Hz ] = . 0665 M
( b ) 3 . e 4 ( c ) 3 . e 4
C}IAPTER 14
.I'}]EORIES OF ACIDS AND BASES
/\cid-Base- _Concepts
f4 .1 (a ) An ac id p rov ides H+(aq) ions . A base prov ides
oH (aq) ions. Neutral izat ion is the reaction between+ -
H' and OH to produce H2O.
(b) An acid provides the characterist ic cation derived
from the solvent. A base provides the characterist icanion of the solvent. In a neutral izat ion thecharacterist ic cation and anion combine to form one
.or two molecu les o f so lvent .
(c) An acid is a proton donor and a base is a proton
acceptor. Neutral izat ion in aqueous medium is the
transfer of a proton from the conjugate acid of water
to the conjugate base of water to form two molecules
o f water .
(d) A Lewis aci-d is an acceptor of an efectron pair
and a base is a molecule with an unshared electronpair whích i t can share with an acid. The neutral i-
zation reaction is the formation of a covalent bond
between acid and base uti l iz ing the base's unsharedp a i r .
l , l -2 (a ) HzO is ne i ther an ac id nor a base j -n the
Arrhenius concept.
(b ) H2O can be e i ther ac id o r base:
H 2 o + H 2 o i H 3 o - + o t t -
ac id l base2 ac id2 base l
(c ) H2o can be e i ther a base ' s ince i t has two
unshared pairs, or a Lewis acid-base adduct. In the
autoprotolysis reaction the acid part of the adductl f l - r a n r n # n n \ a o f q S h i f t e d t O S O m e O t h e r b a s e , i . e . ,\ e ¡ r v r ! v u v
another water molecule in a base displacement
reaet ion .
1 3 . 2 0
L 5 . ¿ L (a ) ONC1 = .436 mo1e. NO = .564 mole ,
(b ) To ta l mo les = 1 .282 mole
(c ) P^- -^ , = .340 a tm, Pr ,^ = .440 a tm 'ONCI NU
(d) .368 a tm
2 . L 9 x l o - 1 0 m o l e l i t e r - r
6 . 7 L x l 0 - e a t m
L 3 . 2 2 ( a )
(b)
L 3 . 2 3 ( a ) f 4 . 4 a t m - '
( b ) x = I . L 2 x
L3.29 (a ) Kp
( b ) - 7 8 1
CI2 = .282 mole
n" r , = .220 a tm
L3.24 (a ) .563 (mole /L í te r )2
(b) K .^ = 8 .77 x 10-4 a tm-2lr'
K = L . ' 7 7 6 ( m o l e / 1 i - t e r ) - 2
L3-25 3 .35 x lo -3 mole l i te r - t
1 3 . 2 6 2 . 4 4 \ 1 0 - 2 a t m
1 3 . 2 7 n * " , = 1 2 . 6 3 a t m , P f O t : 5 0 . 0 a t m , * * n . = ' ' U '
13 .28 n" r . = PnCt , = .75 a tm
Or ig ina l Pec15 = 1 .00 a tm
Percent d issoc . = 75s"
1 O - 3 m o l e l i t e r - l ,
0 ,50 a tn -
atm of NO2; I .22 a ium of N2O4
K = . 0 6 9 4 a t mp
B 3
14.3 Many reac t ions ean be in te rpre ted as redox , e -g- ,
N a H + N H 2 + N a N H 2 + H 2
which in the ammonia solvent system was interpreted
as the level ing of the base H- to the base NHz-, is
also interpreted as an electron transfer betr^teen
H ( 1 - ) a n d H ( l + ) t o f o r m H ( O ) .
In reactions of elementary sulfurr i t can be
considered a reducing agent or a Lewis acid. See
rniddle of page 364 fox such an example, or below:
H - ' S : - + ' é : + H - ' S - 3 r -
Lewis base f,ewis acid
l . 4 . 4
In redox te rms S(2- ) and S(O) reac t to fo rm S(1- ) .
Solvent system: NHaCI + NaNH2 + NaCl + 2NH3
acid base salt solvent
+ -Bronsted: NHq + NH2 -> NH3 + NH3
ac id l base2 ac id2 base l
+Lewi s: NHr*
adduct of
+
T
NHz -> NHg + NH3
base ne\ , r+adduct+displaced base
acid H+ and base NH3
I4 .5 (a ) KOH + HNO3 + KNOg + H2O
(b) CaO + 2H2o + Ca (OH) z
(c ) C lz + H2O + HCI + HOCI-
(d) 2Na + 2H2o '> 2NaoH + H2
( e ) Z n ( O n ) z + 2 N a O H + N a 2 [ Z n ( O H ) ' + ]
| , l .7 (a ) NHz , (b ) Czo+z- , (c ) OBr , (d ) H2Poa
1 , 1 . B ( a ) H g A s o + , ( b ) P H , * r , ( c ) u C z t t s o z , ( d ) H S ,t -
( e ) H P o 4 -
+I , l .9 (a ) NHq r (b ) HzCzO+ , (c ) HOCI ' (d ) NHg
l 4 . l o ( a ) H F + H F ¿ H z F - + F
ac id l base2 ac id2 base l
(b ) HNog + HF ? H2No3 ' + F
base2 ac id l ac id2 base l
( c ) H F + c N ¿ H c N + F
ac id l base2 ac id2 base l
(d ) H2Po4 + co32 i HPo22- + HCo3ac id l base2 base l ac id2
( e ) N z H + + H S O a ? N z H s r + S O 4 2base l ac id2 ac id l base2
( f ) Hc2o4 + HS ? Czo+z- + H2Sac id l base2 base l ac ld2
l . l .1 ,1 See tex t ans \^ ¡ers i o ther examples are :
(a) Hocl + oH -> ocl + H2o
(b) Heo + 02 -> oH + oH
( c ) H C o s * H 2 o ? c o . ' - + H 3 o +
(d . ) NH3 + CHgNHe ? NHr- * CH3NH3+
I t . l 2 ( a ) H z N O H + H 2 O ? H ¡ N O H - + O H5 -
(b ) N + 2NHg - ¡ lNH2-
( c ) H + H 2 o + H z + o H
(d) HSo3 + H2o ? HzsOg + oH
I l . I i (a) An amphiprotic substance may act as a Bronsted
ac id o r base, i .e . r may e i ther donate or accept a
proton.
(b ) Examples are HF¡ HSo3 ¡ N2Hs+, HC2H3O2
: O - H
'l
Lewis base disPlaces iadduct
oH- fron adduct I
Br on s,t-ejl- Iowry _Co.nc ept
L4 .6 (a ) H2AsO3 ¡ (b ) HAsO+ 2- ,
B 4
, . +1 { - o - I i + 0 H
l l1-l r
new adduct ldisPlacedI b a s e
( c ) N O 2 , (d ) s
B5
: O -
@
1 ¡ \ . ¡ i . O
ioH-Ó-se-Ó-H" t "
. ,9 ,o
L4.L4 When an acid is stronger
of the solvent (cation)
that cation.+ -
H C I + H z O + H 3 O + C l
Al1 acids stronger than
so they are " level led"
The same language rs
are stronger than thethe so l ven t ¡ € .$ . r
o z - + H 2 o + o H + o H
H + H 2 O + H 2 + O H
All bases stronger than
14.15 AmPhiPro t ic re fe rs to a
as e i ther ac id o r base '
(usuallY not soluble in
solut ion either bY acid
f
(a ) Ac id sequence: H3o
(b) Base sequence: NH2
Y e s ' ( b ) N o , ( c )
Acid sequence: HSO4
Base sequence: OH
( in anhydrous l iq . H2so
than the characterist ic ac
it is converted comPletelY
r ^ n ñ ó v ñ é n fr v v Y e ¡ v * _ _ *
H3o- su f fe r the same fa te '
by the solvent-
used with regard to bases whi
charac ter is t i c base (an ion) o f
100 Percent
100 Percent
OH are level led to OH '
substance that can function
An amphoteric substance
water) can be brought into
or bY base-
) H3POa > HCN > HzO > NHg
> OH > CN > H2POa > HzO
r,l" Streng-th ang Mgl-ecu]_ar Str_u-cture
. . i ( ) S ince s j -ze is no t chang ing , the grea ter the e lec t ro -negativi ty the stronger the acid. Strength increasestoward the r igh t : AsH3 ( H2Se ( HBr
Size increases goj-ng down a group. This is dominante f fec t so ac id s t rength íncreases l Í kewise .
H e S < H 2 S e < H 2 T e
H 3 P O a ' ( b ) H 3 A s O a , ( c ) H 2 S O a , ( d ) H z C O g ,
9 -
' (d ) NOz , ( : ) so
, ó , Ot . .
: I -O -H
t "" o
(b ) HC10+ is s t ronger than HCl03 s ince i t has alarger formal charge on central atom. But HIO3is s t ronger than H5IO5 fo r the same reason,despite the fact that the oxidation number isgrea ter in the la t te r .
( c ) a c i d : H F + H 2 O
base: HF + HF
a c a d : H > U 3 r
base: HSO3 +
- . - . Í ,a C L O : I \ 2 r 1 5 r
f
b a s e : N 2 H 5 +
a c i d : H C 2 H 3 O 2
base: HC2H3O2
? H 3 o * + F -
? szr ' * + ¡ ' - ( in l iq . HF)
H 2 o ? H 3 o + + s o s 2 -
H z o ? H z S o g + o H
Hzo 7 Nz !tu + Hgo+
? N r H . 2 * + c 1
f
t
+n U I ¿
+ N H 3 Z N t t + ' + C 2 H 3 O 2
* H2SOa I u2c2n3o2* * nsou
N o , ( d ) Y e s
> H C 2 H 3 O 2 >9 -
> C O g - > H S
H2S > HCO3
->
' . . ) . ( a )
( e )
( c ) s a u 3
,ó, ot . .
: C l - O - H
t "' 9 ' oo
( a )
1 . .cl -o-H
I' 9 ' o
H
l s'? ' . /",ó-fó-H
o bljóil "H
H H\ x ' . ' ^ /.X ,V:.
H-O-Te -O-H. . . , \ ¡ . .zY'
'Y\
H H
( a )
I 4 . I O
T 4 . I 7
1 A 1 9 )
t / 4 l o
(b ) HeSeO+ is a s t rong ac id , hav ing a 2+ fo rmal chargeon cent ra l a tom. H6TeO6 is weak, hav ing zeroformal charge on central atom.
( b )
( b ) Y e s , ( c ) Y e s , ( d ) N o( a ) N o ,
B6
> C2H3O2 > SO,r
a 1
The Lewis Concept
L4.26 (a) The carbon atom is an acid
a higher hYbridization it can
electrons' SH- has 3 unshared
a Lewis base '
(e ) sF is the ac id ; H is the
its electron densitY has been
by the hightY electronegative
L4.27 (a ) Be is the ac i 'd center i
hYbrídization i t can accept
F- i s the base '
(g ) E lec t roph i l i c . The ac id A1C13 d isp laces CH3
(h) Nucleophil ic. The base OH displaces I .
t 4 . 2 9 ( a )
(b) H+ must be the Lewis acid' Fe acts as the base
center . A I l i t s 3d , 4s , and 4p orb i ta ts a re f i l l ed
but 4 of al l the ¡á'pairs are unshared and one can be
used for bonding whe-n re goes from dsp3 to d2tp3
hybridization.
(c ) Ag+ is an ac id w i th 5s .and
NH¡ is a base; unshared Paar on
center. BY going to
accept a pair of
pairs on S to make i t
5p orbitals empty'nÍtrogen.
!
H' i s the
point of attack because- so thoroughlY drained
F . F - i s t h e b a s e '
by going to a higher
more e lec t ron Paars '
cenuer.t o s p 3 .
. ^ : ^b a s e . u r >
from sp2 to sP
@ ' . . . @ . , r . tH-O:r*- r$=Q:+ i ' I -O-S=O: ->
I U ' I L it { iot FI :O:^
o " \ i '*z
I I - O - S = O :" l: o :IH
(d ) Th is case is i soe lec t ron ic w i th (b ) ;
ac id an Mn(CO) s - i s the base '
(b) In the f irst step the base center, O, donates apair of electrons to the electrophi le S. In the
second step the nucleophilQ, O-, attracts a proton
in an internal Lewis acid-base reaction.
(c) ahe new structure formed by the migration reaction(step 2) is more stabl-e because al l formal charges are
(b) Hzo is a base and B is the acid
"".upl i"g a Pair from o i t exPands
By
(c) s atom has an incomplete octet ' must be an acid'
t ' - tra= four unshared Pairs' a base'
(d) H- has one unshared p4ir ' a strong
acid center; can accePt a Pair and go
(e) Au is ac id center i CN is a base '
L4.2a (a) Nucleophil ic ' The base H i l isplacesf _ .
NHz .f
Noz .(b ) E lec t roPh i l i c ' the acid H' i l isPlaces
(c) Nucleophilrc ' The base Cl displaces H2O'
(d) Consider GeS2 an adduct of the base GeS and the
acid :s: . Then t ie aispfacement is nucleophil ic '
the base Ge disPtaces GeS'
(e) nucleophil ic ' The base 02- displaces oH
( f ) E lec t roph i l i c ' The ac id FeBr3 d isp laces Br
BB
q o
CHAPTER 15
IONIC EQUILIBRIUM' PART I
- 5 = ¡ o H - l ; [ c o H s N H z ] ' 3 0
1 5 . 1 3 3 . g x l o a
1 5 . 1 5 I ' 0 x 1 O - 3 t " t
t N ; l = o . l 3 M ; [ H N a ] = o ' 1 0 M
, , , l l r "a t ion o f Water , PH
t , - 2 L ( a ) [ H + ] = 2 . 0 x 1 o - 2 M ; i o g - l : 5 . o x l o - r 3 l ¿
( b ) t o H - l = . 0 4 0 M ; [ H + ] = 2 . 5 x 1 O - r 3 u
t " . 2 2 ( a ) O . 4 6 t ( b ) 1 3 . 1 8 ' ( c ) B . 7 8 ' ( d ) 7 . 6 0
t ' , - 2 3 ( a ) 4 . 1 4 , ( b ) l . O B , ( c ) 1 0 . 5 2 , ( d ) 1 2 - 6 2
t " - 2 4 ( a ) 4 . 7 x l - O 4
M , ( b ) 2 . 1 x 1 0 - r r
M ,- 3
( c ) 1 . 3 x 1 0 M
- 1 4( a ) 3 . 5 x 1 0 ! 1 , ( b )
( c ) 1 . 3 x 1 0 -
M , ( d )
l - l x l o
. r t
r t . 3 6
p H : 6 . 5 7 t o p H = 8 . 3 5
( a ) 9 . 6 < p H < I O . 0 , ( b ) 5 . 5 < P H ( 6 - 0 r
( c ) 4 . 5 < p H < 5 . 0
, r l n r ( ) n - I on E f f ec t , Bu f f e r s
r ' , r . ' l ( a ) p H - 4 . 3 5 ( b ) o . r B %
( b ) . 4 6 e "
- 6
1 5 . 3 7 3 . 2 x l - 0 -
1 5 . 3 9 0 . 7 1 M
1 5 . 4 f 4 . 5 x 1 0 - 2 t ' l
l c z H s o z l / I H C ú t s o z ] = 6 . o / L . O
' ^ " ' T t
/ f r t r r I - ^ t rr r l n 4 l / [ r l n 3 ¡ - . . . 6
Vüeak Electrolytes
- +1 5 . 1 l - 5 x l 0
- 3I 5 . 3 3 . 9 x 1 0
- 71 5 . 5 7 - 3 x 1 0
1 5 . 6 ( a ) 0 ' 0 8 2 M
- 4
: l . 5 . 7 4 . { x l 0 M
- ?
1 5 . 8 ( a ) 3 ' 5 x 1 0 -
M
- 3
1 5 . 9 ( a ) I ' g x 1 o
+ -15. lo (a ) [ r i - ] = loc r ]
( b ) 0 . 1 1 2 m o l H C I O z
( b ) 1 . 8 e "
( b ) . 7 2 %
= 8 . 0 x l O - s ; t H o c l l = ' 2 O
- 2" ? X
2 . 3 x
l 0
- 51 0
t ' , - 2 5
t " - ) - 6
t , , . , 1 8
1 , ' . t 0
l " . \ 2
| , . J l
- 5
4 . 8 x 1 0 -
1 1 ,- l ?
4 . 6 x I 0 - "
M
- 31 5 . 2 7 3 . r x l 0
- F ,
1 5 . 2 9 7 . 3 x l 0
- 6
1 5 . 3 1 2 . 5 x l _ 0
L ) . L ¿
15 .14
l 5 . l - o
I f , . I '
L ) . r o
1 ( l q
1 R ? n
(b) o - 04e"
+
l C o H s N H g I =
. I B M
0 . 3 I %
t H ' l = l ' 5 x
- 4
3 . 9 x l 0 M
1 . 2 x l 0
rH+r = '-i I ':^l^.:J'i.:ll::i ;:i::""::'ffi"i:::":-10 M benzo ic acrd
lNH,*+ l = 2 .7 x l0 -5 M; A l t the NHac l reac ts to p
. i i - * ' N H 3 a n d l e a v e s ' 1 0 M o H - '
[Nn, *+ ] = 5 .4 x lo -s M; A l l the NHa+ reac ts to p roduce
. I S - * - N H 3 a n d l e a v e s ' 0 5 M o H - '
t ' , ( a ) 3 . 8 0
r { , 5 - 5 x 1 0 -
r i t O . 7 0 M
l i ) 4 . 8 5
| 5 . 4 I
90
t ¡
91
- 3
1 5 . 4 5 7 . 8 x I 0 -
m o l
Polyprotic- Acids
t s .46 (a ) t co r l 1 -63* ' [H* ] = [HCo3 ]
t c o ? - l = 4 ' a x 1 O - r r '
( b ) 3 - 9 2
L5 .4 '7 [H - ] = tH2Aso ; l = 8 ' 5 x 10 3 M ;
¡Heso i ) = 5 ' 6 x ro -8 ; t aso i - l
1 5 . 4 8 ( a ) t s ' - l = 4 ' 9 x 1 o - 2 r M
(b) [Hs- ] = '7 '4 x ]o-8 ¡ ' t
L 5 . 4 g t s 2 - l = 4 . 4 x 1 0 - 1 6 M
15 .50 [ i l + ] = 1 ' 9 x l o -3 l ' l
Ions that function as Acids an
= 1 . 2 x 1 0 i
[ H g A s O + ] = 0 . 2 9 M
= 2 x I O - '
M
t l / \ t rTER 16
I i }N IC EQUIL IBR IUM, PART I I
I l ' , . q ñ l r r t r i I i l - r ¡ P r O d U C t-:-::=.--: ]---.--.- l !
l r , . L 2 . O x t 0 - '
_ o ^
. 3 2 . O x f O ' "
CuCOg (molar so lub i l i t y , 1 .6 x 1O-" l¿ ) i s J -ess _uso lub le than Ag2CO3 (molar so lub i l i t y , l - .3 x 10 M) .
CuS (molar so lub i l i t y r 8 .9 x l -O- re) i s less so lub lethan Ag2s (molar so lub i l i t y , 1 . I x 10- i7 ¡¿) .
- l L
l t , . l 2 . O x 1 0 - '
- 7l r , - , ) 5 . 6 x I 0 m o l A g 2 C O 3
t r , , ip Í ta t ion and Ksp
t + - 1 1l - 6 . 8 I N i - 1 = 3 . 3 x l 0
- - M
l ' , - l t ) T h e f i n a l c o n c . o f N a - i s 0 . 1 6 M a n d o f C I i s O . 3 O M1 l - h a < a i n n q ¡ f a ñ ó f r a a . l - )\ e ¡ ¡ e s u ¡ ¡ v v ! v s v s , .
t - - a
l B a ' ' l = O . O 7 O M ; t c 2 b [ 1 = 2 . L x I 0 M
r r , . I I t N O ; l = . 1 5 M ( N O l d o e s n o t r e a c t ) ;
Final- [ tr ta-1 = . OrO (no reaction )
A f t e r r e a c t i o n [ s r 2 + ] = . 0 3 0 ; t r I = 1 . 6 x I 0 - 4 l ¿
r r , l . l i r I = 9 . 5 x 1 O - + M 1 6 . 1 3 8 . 3 x 1 O - B
+I r , | , ' r tNn[1 = ! .2 . M 16. 15 tNu i l = . 21 M min imum
¡ ¡ , l ( , [ N H ? ] = 3 . 6 x l O - 3 M m i n i m u m
I t [ N H 3 ] = . 1 8 M
l r t C a ( O H ) 2 w i l l n o t p r e c i p i t a t e .
1 6 . 2 3 . 7 x r 0 q
7 6 . 4 2 . l - x 1 0 "
M
M
1 5 . 5 1 B . t B
1 5 . 5 3 8 . 6 1
1 5 . 5 5 0 . 6 0 M
1 5 . 5 7 4 . 3 x 1 0
1 5 . 5 9 5 . A 2
lgid-Base Titrations
1 5 . 6 1 ( a ) 3 ' 9 2 t ( b ) 8 ' 4 6 '
L 5 . 6 2 @ ) 9 . 4 4 , ( b ) 5 ' 2 B l
- 6
1 5 . 6 3 6 . 2 x r 0
L 5 . 6 4 2 2 - 0 0 m l
L 5 . 5 2 2 . 8 2
1 5 . 5 4 4 . 5 0
1 5 . 5 6 7 . L x 1 O - 2 M
1 5 . 5 8 2 . 9 x I O -
1 5 . 6 0 . o 7 B M
@ ) L 2 . L 6
( c ) I . 7 8
9293
Precipitat ion of Sulf ides
16.19 No Prec iP i ta te fo rms '
L6.20 l lo PreciPitate wil l form'
L6 .2L CdS wi l l Prec iP i ta te '
L6 .22 [ t l * ] = o .z3 (min imun)
L6-23 [H+] = 0.47 minimu¡n
t 6 . 2 4 [ P b 2 + ] = 2 . 3 x 1 o - 7
L 6 . 2 5 [ H + ] = o . 7 O M , l S 2 - l = z . z
l c , r t + l = 3 . 6 x l o - r s M ' [ F e
16.26 [H- ] must exceed 0 '086 M'
16 .27 (a ) tn+ l = .30 min imum
( b ) [ P b 2 + ] = 3 x 1 0 - 7 ¡ t
Complex Ions
l . 6 . 2 8 ( a ) 2 - 4 x
( b ) 1 ' 4 x
( c ) 1 ' 9 x
L6.29 AgCl w i l l
l0-2 mol,/ l i ter- ?
1 0 - M- 5
l 0 M
not p rec iP i ta te .
- 2 2x 1 0 M '' ' l = 0 . 3 0
I IAPTER I7
I I,I.JMENTS OF CHEMICAL THERMODYNAMICS
' t ' l rrr Fir j ; t Law, In_terIral_Energyr_ Enth_alpy
I l .L The f j - rs t law essent ia l l y s ta tes tha t energy isconserved during a physical or chemical changer butmay be t rans formed. I t i s usua l ly s ta ted :AE = q - w, where AE is the change in internalenergy content of the system, q is the heat absorbedand w is the work done by the system during thechange. Entha l -py , H, i s de f ined by t ¡ = E + PV. I tdif fers from E by including the PV product of thesys tem (wh ich a lso has un i ts o f energy) .
| 1.2 A state function has a value dependent only on thes ta te o f the sys tem ( i .e . , i t s tempera ture , p ressure ,vo l -ume, compos i t ion , e tc . ) and is independent o f howthat state was achieved. A1l the state functions inChapter L'7 are slmbolized by upper case letters.T h e y a r e z P , T , Y , E , H , G , a n d S .
( a ) - 1 3 6 4 . 3 k J , / m o l
( b ) C z H s O H ( 1 ) + 3 0 2 ( g ) - >
a h l - - l _ J ( ) b . ó J < J
( c , - ¿ t t . 9 K J l m o r
(a) -1170 kJ lmo l
( b ) c s ( N H z ) z ( s ) + 3 0 2 ( g )
2 c o z G ) + 3 H 2 o ( l )
Since An = o , AH" =
-92 ;2 kJ , /mo l
-3911.8 kJ lmo l
+ coz (g ) + so2 ( s ) + Nz ( s )
+2HeO (1 )
A E o = - 1 1 7 0 . 0 k J
C e H r z ( 1 ) + 9 0 2 ( 9 ) + 6 C O z ( g ) + 6 H z O ( f )
AHo = -3919.2 kJ /mol -
( c ) - 1 5 7 . 2 k J / m o L
AEo = -5459.55 kJ
/ ¡ \
I t . ' , ( a )
( b )
94
r'
L7 .7 AE" = -1405 '8
L7 .g AEo = -726 '66
17 .11 +81 .69 kJ lmo l
t ? _ l ?
L7 .8 aE" = -66 -57 kJ
17.10 -LBA-79 kJ lmol
S i n c e a l l s u b s t a n c e s i n c l u d i n g e l e m e n t s h a v e a b s o l u t eentropies, there is nothing to be 9ii":1^?Y..tabulatinformation values- (Such values could easi ly be
calculated from the formation reactions and the
abso lu te en t roP ies ' )
L 7 . I 4 ( a ) + 1 0 3 . 0 J / K ( b ) - 5 8 7 ' 6 k J
1 7 . 1 5 ( a ) - 4 9 . 2 J / K ( b ) - 1 4 s 9 ' 7 k J
L7.L6 F i rs t reac t ion AGo = +267 '4 kJ
Second reac t ion AGo = -207 '0 kJ
S e c o n d r e a c t i o n i s s p o n t a n e o u s ; f i r s t i s n o t .SOz and H2 react lo produce HzS and HzO'
L7.L7 AG" = -675-5 Yes , i t i - s poss ib le '
17 .18 BF3 is s tab le to hydro lys is ; BCl3 w i l l hydro lyze '
L \ .Lg (a ) s ince AGo fo r the reac t ion is pos i t i ve ' i t i s
not sPontaneous'
( b ) A G " = - 4 1 ' 6 k J
Spontaneous reactiont yes preparation is possi
L '7 .20 (a ) None of these preparations is spontaneous at 25
because AGo is Pos i t i ve '
Since Aci is less Posit ive for
the combustion of NO to NO2 is
general ly the decomPosit ion of
to the elements is spontaneous96
| / . 2 I A G o = - 4 8 . 3 9 k J ; y e s , s p o n t a n e o u s
| / . .¿2 AGo - -467 kJ¡ yes , spontaneous
I t . . . 3 ( a ) - 1 0 1 , 0 1 , ( b ) - L 2 O . 6 J / K , ( c ) - 1 2 0 . 6 J / K
| / . ) .4 +63.6 kJ,/mole
1 / . ) 5 ( a ) A G o = + 3 8 . 3 k J S i n c e A G " i s p o s i t i v e , i t i sNOT spontaneous.
(b ) Ac ' = -11 .8 kJ Yes , i t IS spontaneous a t 300"C.
11. .¿6 (a ) AGo = +130 kJ No, no t spontaneous a t 25oC.
(b) Aco = -26kJ Yes , spontaneous a t 1000oC.
1 I . . ' .7 (a ) AGo = -139.9 Yes , spontaneous a t 25oC.
(b) AGo = +2I .4 No, no t spontaneous a t l200oC.
l / . . : 8 2 3 9 . 7 K o r - 3 3 . 4 " C
! I . . ' . ' ) 3 4 2 . 2 K o r 6 9 . 1 o C
1 / . r 0 + 1 8 . 2 5 k / m o l
I / . | | ( a ) - 1 2 8 . 1 k J , ( b ) - 3 3 2 . 3 J / K , ( c ) - 2 9 . 1 k J ,
( d ) - 1 6 6 . 4 k J
I t . t . , . 2 o a J / K 1 7 . 3 3 2 0 5 . 5 J / K
I t . t4 So (d iamond) = 2 .438 J /K mol . S ince S" (g raph i te ) i s5.694 J/K moL, the diamond crystal is more ordered(Sova lue lower ) .
i / r ' , - 1 0 9 5 . O k J
; I l , t ,r ; . t¡ree Energy and_ Equil ibr ium
I i r { , 5 . 1 2 x 1 O - " 1 7 . 3 7 0 . 4 4 3
I i i l r 1 . 4 4 x I O G I 7 . 3 g 2 . O 7
| 1 . l r ) - 5 5 . 2 k J , / m o l L 7 . 4 I + 3 8 . 5 k J
l / | . ' A c o = + 7 g . g k J ; K = 1 . 0 * , O - t u$/
KJ
Áu
I7.L2 A change is spontaneous i f i t results in an increase
in the total lntropy of the universe' I f one observe
only the "V"tt*, tirá criterion is that it \n/ill change
sponcaneouufy i t i ts Gibbs free energy decreases'
Since there are no absolute H and G scales i t is
convenient to tabulate formation values for compound
I
ILI
(b )NOz than for NO,
spontaneous. But
the nitrogen ox
i n a l l c a s e s .o?
L l . + 5
L 7 . 4 4
+27 kJ
@ ) - 2 A . 4 8
( d ) 3 3 . 6
l l ; r l " f E R l B
} I , I I ( ' , IROCHEMISTRY
K J , ( b ) - 4 2 . 6 7 J / K ' ( c ) - 1 6 . 7 5 k J ,
' ¡ , l r , l t r c t i O n
In metal l ic conduction moving electrons carry the
charge; j-n electrolyt ic conduction moving ions carrythe charge.
As a metal is heated the vibrat i-ons of the atoms about
their latt ice points interfere with el-ectron f l-ow and
res is tance increases (conduct ion decreases) . As asolut ion is warmed it becomes l-ess viscous, ions canmove more f ree ly . and i t s conductance increases .
Anions are attracted to the anode.
Oxidation occurs at the anode.
The anode is pos i t i ve ly charged.
Electrons move from some species (usually insolution) into the anode and thence to theexternal po\¡/er supply.
r olyt ic Ce11s, Quanti tat ive Re]atignFhips
Anode
cu*cu2*+2e
( a )
( b )
( d )
9B9 9
,{
I U . b ( a ) cathode 2H2o + 2e + Hz *
Anode 2H2O2+ O + 4H+ +
Cathode 2H2O + 2e -> Hz *
Anode 2CI -> CL2 + 2e
Cathode crr2* + 2e + Cu
Anode 2CI -> CL2 + 2e
(d) cathodu cu2+ + 2e + cu
Anode (inert) 2H2o -> 02 1
20f1
4e
zví
+4H' + 4e
( b ) . 8 6 7 A
( b ) 4 . 2 9 m i n
I 8 . 1 6 2 8 . 6 s e c
1 8 . 1 8 2 8 . 3 7 9 C u
(b)
( c )
18 .7 . 5709 l l i
lB.B g io+ + 2H+ + 3e + Bi + Hzo '9759 Bi
18.9 (a) pb2+ + 2 lzo + Pboz(s) + 4n+ + 2e
(b) .558 g Pbo2
(c\ 46-6 minutes
1 8 . 1 0 1 0 . 0 6 I A g
1 8 . 1 2 2 8 8 m i n -
1 8 . 1 3 ( a ) 7 B o c
18 .14 (a ) . 15659 N i
1 8 . 1 5 3 3 3 . 8 I c
18 ,17 9 .21 l i t e r
1 8 . 1 9 1 . 1 9 M
I B . 2 O ( a ) 5 . 0 0 l i t e r
La .2 r ¡ cu2+ l = 0 .358 Mr
L8.22 5.77 hours
L 8 . 1 1 2 8 . 6 m i n '
i
I
( b ) . 8 9 3 M
t c l - l = 0 . 7 1 7 M
r¡ , , L ta ic Ce l ls Electrode Potentials
M g 'Anode
t.LMgrMg-'+2e
5" (ce11) = Eo(ca thode) - E" (anode) = .799 - ( -2 .363)
=+3 . l - 62 V
c d - _ Pr , C1-2
Cathode
CLr+2e'+2CL-
Eo ( ca th )
AgCathode-L
Ag'*e +Ag
Anode
cd*cd2++2e-
E" (ce1 l ) = - E ' (an ) = 1 .3595 - ( - . 4029 )
= L . 7 6 2 4 v
l r t . . l s ( a ) 2 . 2 7 v , ( b ) s n z + + M g + S n + M g 2 + ,
(c ) Sn e lec t rode i r @
l r r . . 2 6 ( a ) . 5 8 7 V , ( b ) C u 2 + + N i - > C u + N i - 2 + ,
(c) Cu electrode i" @
I u . . '7 (a) pr I t , (") | r- (.ql l l cr- 1aq¡ I cr, (s) I n.( b ) E " = . . 8 2 4 0 y
(c) The cf2 lc1- e lect rode is the cathode.
r , 1 r r r (a ) p t I n r ( s ) l n * ( *s ) l l n r - l 1aq ¡ l " . r ( r ) l n .( b ) 1 . 0 6 5 2 v
(c) The anode is u2 lH+
I i l . r , ) - 1 . 7 8 9 V 1 8 . 3 0 . 9 8 7 V
r01
1 8 . 3 1 - 3 2 0 v
L8.32 (a) suitable oxidizi"g "s""li ":".t:,:::
arrows (?) and below Fe-' ' but above
o"fY o""" ' in APPendix E are (reducedq + 2 . +
4 r
parenuhes is ) : g t t * 1c t ' - ) t cd '
(cd) ;
Pbso+ (Pb ) '
(b) cea+ (cd3+) ; Hocl (c le) ; Pboz (Pbso+) ;
NoT stable.
In
Yes, and the product wi l- l- be In3*+ + + 3 +
3In + 2 ln + ID , 2 In + 6H -> 2 In * 3H2
2 ln + 3C12 + 2 In3* + 6C1
Tl-- rs stable.+
T1
Yes, T l -r ? + +
3T1t + 2,rr + Tf "-,
2T1 + 2H- -> 2Tr- + H2,+ 3 + + -
2TL + 6H' + 2Tt- + 3}lzt 2TL + Cl2 + 2TL + 2CI '3 +
2Al + 3CL2 -> 2'¡1- + 6C1
No, (b ) YES, (c ) NO
- 1 . 2 0 8 V
t i2+ rs s tab le .
t i wi l l react with H+ to give Ti2+.
l . B O B V
Co2+ wil l NoT disproport ionate.
co wil t react with H+ to produce co2+.
+ . 0 4 0+ + 2 + 4 +
2uOz + 4H -> uoz + 2H2o + u+
wil l disproport ionate.
L . 3 9 7 V+
YES Au' wi l l not disproport ionate.
Au wil l not react with H+.
- 3 . 3 9 6 V
No, Eu2+ wiII not disproport ionate.
YESt +
YES, Eu- w i f l be fo rmed.
left of theT
Tl ' . The
form in
and
- 3 7 ( a )
( b )
( c ,
/ ¡ \
. 3 8 ( a )
( b )
( c )
t q ,
. | e ( a )
. . ¡ 0 ( a )
( b )
( c )
. , 1 | ( a )
( . l ] /
( c )
r . r ( a )
( k )
uoz
r r ( a )
(b )
( c )
l t ( a )
( b )
( c )
( d )
+
Au, 1au)
(c) Invert the procedure of part (a);
ca (ca3+) i c r1c r3+ ) ¡ zn (zn2+ ' , - - - . t , - , 3 t r
( d ) e u + ¡ a u 3 + ) t c t ( c r z ) ; c r " ' ( C r 2 o 7 ) ' � r r \ r '
18 .33 ( - ) ag+ (A9 ) ; No ¡ (Nzo ' � * )
(b ) r r " ' ( r r )
(c) Hzs (s) ; nz (s+) t Pb (Pbz+)
(d ) S (Hzsos )
18.34 (a) The react ion wi l l NOT go as wrÍ t ten '
(b) H2o2 + 2As+ -> 2H+ * 1?
* o'3 +
( . ) Rg+ + Fe' - + Ag + Fe
(d) No
(e ) HzSog + 2H2S + 35 + 3Hzo
18.35 (a) Pbo2 + 2CL + 4H+ -) Pb2+ + CLz + 2H2o
(b) No
(c) 2NOs + BH+ + 6r + 3rz + 2No + HzO
( d ) NO r
(e) 2Mnor+ + 3Mn2+ + 2l1zo + Sllnoz * 4H
18 .36 (a ) Hg + H92+ -> Hgzz+
(b) No
(c) No
(a) 2un3+ -t NIn + 3N1n''h + ^ - 2 +
( e ) s n ' ' + s n + 2 s n
L021 0 3
,ff
I
Gibbs Free EnergY and einf
rB .4s (a ) pb leusoa ( s ) l so42 - l l e r2+ leu(b) pb2+ * so42 + Pbso+ (s)
( c ) + . 2 3 3 v
( d ) - 4 5 . 0 k r
re .46 (a) Aglasr(s) l r - l lae+les(b) es+ + r- ? Agr
( c ) - 6 4 7 v
(d ) -62 .4 kJ
L8.47 (a) Pt lo , ts l lon- l lu* loz tg¡ Ip t
( b ) o . B 2 B V ' - 7 9 ' 9 k J
, ¡ * r r f( a ) P t l " r t s l l n - l l " ' l o r t s l l e t( b ) 1 . 2 2 9 v , ' 4 7 4 . 4 k J
( a ) 0 . 2 9 4 3 v ' ( b ) - 5 6 . 7 9 L k J ,
( a ) . 5 4 7 v , ( b ) - 2 1 I ' 1 k J ' ( c )
( a ) . 3 9 3 5 V , ( b ) - 7 5 . 9 k J ' ( c )
( a ) - 5 0 9 . 5 k J , ( b ) ' 4 3 ' 5 k J m o l e
- l
-963 .1 kJ mo l -
( a ) 1 2 5 . 2 k J , ( b ) 1 . 7 6 5 v '
( c ) H z o z , c o t * , s z o e 2 - , C � 3 , F 2
K = 7 . 2 x 1 0 3 l - 8 - 5 6 K = 2 ' 7 x 1 0
- 1 4- I J
K = 9 . 9 x 1 0 " " o r ^ r 1 . 6 x 1 0
l 1K = 1 . 2 5 x L O " 1 8 . 5 9 - . 2 8 4 V
I r r . 6 l ( a ) 2 . I 5 7 V
(b) M9 + N i2+ * Mg2+ + N i
(c ) l ¡ i i s lhe * e lec t rode.
1 8 . 6 2 ( a ) 2 . 2 4 0 7 v
(b) zn + C12 * zn2* + 2CI
(c ) zn is negat ive .
¡ r r . 6 3 ( a ) - . 0 0 6 V
(b) Because of the departure of the actual con-centrat ions from the standard. states, the actualvoltage is opposite in sign from Eo so thereaction proceeds in the opposite direct ion fromthat predicted from the Eo. Spontaneous reactioni s :
2 + TH 2 + P b - ' P b + 2 H
(c) The ca thode is the pos i t i ve e lec t rode, wh ich inth is case is Pb.
1 ¡ r . r , 4 2 . o 4 M 1 8 . 6 5 . 0 2 3 9 M
1i l , { , ( i (a ) NOT spontaneous.
(b) Now reaction IS spontaneous.
l i l . r , / + 1 . 1 9 V
iu . r , r t (a ) When ¡ t " t2+1 is doub led the reduc t ion po ten t ia l
inc reases (a lgebra ica l l y ) by .0089 V.
(b) Cutt ing [ lut2+] in half lowers the voltage by. 0 0 8 9 v .
] u . r , r ( a ) + . 0 1 0 V
(b) The concentrat ions at the end depend on therelat ive volumes of solut ion. I f the volumesare equal and both solut ions are 1.00 M to start,then
l s n 2 + l = 1 . 3 7 0 M ; [ P ¡ 2 + ] = 0 . 6 3 M .
on the other hand i f the volume of sn2* greatly
exceeds pb2+, then [srr2+] wir l hardly change while2 +
l P b I w i l l g o t o . 4 5 9 M .
I B . 4 8
I B . 4 9
1 8 . 5 0
I t , . ) I
18 .52
1 8 . 5 3
l ó . f , q
1 8 . 5 7
1 8 . 5 8
( c ) - I 2 1 . B
+ 7 2 . 6 8 J K
- 7 2 . 4 k J
- l
JK
The Nernst Equatlon
2 +1 8 . 6 0 R e d u c e [ F e - ' l , r e d u c e P " . r t n c r e a s e
n 2
104
f
105
If vice versa' [Pb+] "/iU hardly change and
lsrr ' * l wi l r 9o Lo 2 'L77 t4 '
1 8 . 7 0 ( a ) . 1 3 6 v
(b ) p t lH r I tH* t = .o25 l l [H* ] = s ' oo I n2 le t
( c ) . L75v
. 0 1 6 3 V
Ga (an) + Ga3+ (ca t ) ? Ga3+ (an) +
The anode, i .e . , the Ga in contac t
Gat* , i s the negat ive e lec t rode '
+
L8.72 The discharge reaction consumes H2Soa' The H -
combine with the o in PbO2 to form water while SOa
goes io for¡n PbSO+ on each electrode' As H2SOa is
removed the densitY is reduced'
1 8 . 7 1 ( a )
(b )
( c )
Ga (ca t )
w i t h . 3 o o M
106
TER 19
NONMETALS, PART I: HYDROGEN AND THE TALOGENS
¡ ly ( l rogen
l ' , - l w a t e r ( H 2 O ) , h y d r o c a r b o n s ( C H q ) , l i v i n g m a t t e r .H2 can be obtained from water by reduction with C,hydrocarbons, iron; or by el-ectrolysis of v¡ater.
2Na + 2H2O -> 2NaOH + H2
3Fe + 4H2O -> Fe3O4 + AHz
Similar reactions can be writ ten in which theproduc ts a re FeO and Fe2O3.
(c ) zn + 2H+ * rn ' * * n ,
(d) Zn + 2OH -> ZnOz2 + Hz
( e ) C + H 2 o + C o + H 2
( f ) cH4 | H2o + co * 3Hz
( g ) C a H 2 + 2 H 2 O + C a ( O H ) 2 + 2 H 2
l ' r . ] ( a ) H z r 2 N a + 2 N a H
(b) He + Ca + CaH2
(c) Hz + c12 + 2Hc l
(d ) 3H2 + Nz + 2NHs
( e ) C u z o t H 2 + H 2 o + 2 C u
( f ) co + 2H2 + cHsoH
( g ) W O ¡ + 3 H z + W + 3 H e O
(a) Salt l ike hydrides are ionic crystals, hard sol ids. . i + L L ' i - L * - .wrL¡ ¡ ¡ ¡ayr r * , . y . r and conduct e lec t r i c i t y whenmolten. The hydrogen is a negative ion.
(b) Interst i t ial hydrides resemble the parent metalin structure and propert i-es. The hydrogen ispresent as single neutral atoms in interst ices inthe metal latt ice.
(c) Conplex hydrJ-des are salts. The negative ion hasa central metal atom (e.9. B) surrounded byhydrogen a toms (e .9 . BH4- ) .
( a )
( b )
ütr- -
(d) Covalent hydrides are formed with all the non-
metals and are usually simple l iquids or gases
(e .g- HCl ) ; bu t w i th B , C, and S i compl ica ted
structures can result (e.g' hydrocarbons l ike
C s H r s ) .
19.5 Since Hz exhibits the least London force' H2 is the
most volat i le stüstance aside from Het and is not
very soluble in l iguids'
(d) 6Cr- * Cr2O72- + I4H+ -> 2Cr3* + 7H2O + 3C1z
(e) OK for Br2 and 12 but not for F2 since Eo (red)of F2 is more positive than that of any of theoxidizing agents above.
l e . L 4 ( a ) C a F 2 ( s ) + r ¡ e s O 4 ( 1 ) + r * ( n ) + C a S o a ( s )
2t{F(r) 4F- H2 * F2
(b ) 2Nac1 (1 ) " I t t t t , 2Na + c12
- (c) 2Bx + C12 + 2Cl- + Br2
(d) 5NaHSO3 + 2NaIO3 + Iz * NaHSOa + 3Na2SO+
* H2SO¡+ * H2O
(See answer key in text for an ionic reaction)
(e ) PBrs + 3H2O + 3HBr + H3PO3
These sol ids are very effect ive because of their
abi l i ty to dissolve hydrogen in the form of atoms'
thus making them very available to react with other
substances adsorbed on the surface.
1 9 . 6
1 9 . 8
1 9 . 9
1 9 . r 0
. 5 0 3 9
2 . O L 6 g o f
2 6 . 8 7 g o f
8 - 9 2 g o f
5 8 . 8 7 I o f
- 2 7 0 k J
-44 kJ
A H - o t s :f
-244 (b) ¡
( a ) (b) . e58s
H 2 ( b ) 2 8 . 8 9 g o f A i r
l i f t , 13.33 t i¡nes i ts own $/eight
( a )
( c )
( a )
( c )
( a )
( c )
(d )
lij
L l
I
l li
(b ) 32 .43 g o f zn
( a )
(b )
( c )
( d )
( e )
(s)( h )
( i )
H2 t C l '2 - ) 2HCI
Zn + C12'+ ZnCL2
2 P + 3 C L 2 + 2 P C 1 s
2 3 + C l - 2 + S z C 1 z
HzS * 2C!2 -> 2HCl + SC12
c o + c 1 2 + c o c l z
SO2 + CL2 -> SO2C12
3I + CL2 -> 2Cl + 13
H2O + CL2 -> HOC1 + HC1
- l - l
mole b l '244 kJ mole- l
mole -
H f " , - 2 6 9 v s - 2 7 0 ( a ) ; H z O r - 2 4 1 ' 8 v s
N H 3 ¡ - 4 6 . I 9 v s - 4 4 ( c )
- t1 0 l l A"" = -Bo5.B kJ mole
Result is very close to NaCl latl ice energy
that the lattices are similar in arrangement
The larger value for NaH is consistent wÍth
smaller size of H- compared to C1-'
L9.L2 (a ) 26 .09 g o f H2 (b ) 289 '8 l i te rs o f H2
The Halogens
r ' r - f6 (a ) 4Hr + s io2 + s iFr+ (g ) + 2H2C-
(b) Na¿COa + 2HF + 2NaF * COe + H2O
(c) HF + KF + KHF2; contains FHF ion
(d) CaO + 2ItE -> CaF2 * H2O
(See answer key for some alternatives and some ionicreactions)
+ F ( a )
i ¡ 'ur- (H bonded) (b)
indicatiand size
the
( a )
( b )
( c )
2CL
2CT
IOCI
* MnO2 +
+ PbOz +
+ 2MnOa
+ 2 +4 H + M n +
+ 2 +4 H ' + P b +
- + l 6 H i + 2 M n
l0B
2H2O + CL2
2f12O + CL2t * * B n r o + 5 c 1 2
. - L
nr <- t1
F + H F
1 9 . t 3
109
tw*
HF is a weak ac id , Eq(a) , bu t in very concent ra ted
solutÍons, reaction (b) removes F- and drives reaction
(a) to the r ight. At moderate and 1ow concentrat ions'
reaction (b) is unimportant and i t behaves l ike a
nonnal weak acid'
l g . l 8 o n e m u s t u s e c o n c e n t r a t e d H 2 S o a t o d r i v e o u t t h ev o } a t i l e h a l o a c i d , a n d c o n c e n t r a t e d H 2 S o a i s a s t r o n g
enough oxidizing agent to oxidize Br- ' to Br2' The
result is a mixture of FIBr and Br2 in the product gas'
The above two Ag
CI2 + 2Br '> 2CL
CI2 + 3I -> 2CI
Also very di lute
t 9 . 2 4 2 8 . 2 F
1 9 . 2 5 8 8 6 g o f C 1 2
l ' ) .26 L323 g o f CI2
salts doe not redissolve in
+ Bxz 1i9ht brown
* Is deep brown
Is * starch + blue complex
N H s .
l
19 . 19
Lg.2O XX 3 is an AB3E2 molecu le t o f
PYramidal Pairs' two tr igonal
giving a T-shaped molecule'
( a )
(b )
( c )
FeCl2 ' Fe I I I more cova len t than FeIT
RbCl, GrI more metal l ic than GrII
BeF2, F more electronegative than Cl. so i ts
compounds are more ionic.
(b) 2NaCl + 2H2o
(c) 2NaCl + 2H2o
(d) 6NaCl + 3H2o
(e) r¡aclOg + H2O
L9.22 (a ) HCf ' (b ) CIz '
( d ) F z , ( e ) C l e II
' L
1 q . 2 3 c a - ' + 2 F + C a F z ( s )
the 5 tr igonal bi-
pairs are unshared,
2Na + C12
e l e c t r . ^ ," * * - - - ) C L 2 + H 2 + 2 N a O H
elec t r , H2 + Nac l + Naoc l
e l e c t r . ^ - -< Jf lz | ¡rqi l- + NaClOg (s)
e l e c t r . - - , i , ^ ^ r A+ f l 2 f l \ d u t v 4
(c ) HF (u bond ing e f fec t ) ,
( f ) c l z
XX s j-s ABsE; 6 octagfonal pairs' one unshared;
square PYramid.al molecule 'I
XXt , pentagonal bipyramid, no unshared pairs'
Lg.2L (a) 2NaCr e lect r )
Ag* + cl ->
AgCl + 2NH3
Ag- + Br ->
Ag+ + Í- ->
AgCl (s) white
-> Ag (NH3 ) ,* *
AgBr (s) cream
AgI (s ) ye l low
c1
color
1 1 0 111
W
l l
l i i
i ,
IL
l
l
i
( e ) 2PbS + 3O2 + 2PbO + 2SOz also
reactions which produce higher oxides of pb sucha s P b 3 O 4 .
C H 4 + O z + C + 2 H 2 O
2 C H a + 3 O 2 + 2 C O + A H . O
CH+ + 2O2 -> CQz + 2Hza
CHAPTER 20
THE NONMETALST PART 11: THE GROUP VT A ELEMENTS
2 0 . 5 ( a )
( b )
( c )Oxygen
2O.L Free oxygen in air ' in H2O' in carbonate and sil icate
rocksf in l iving matter' Get oz by l iquifaction and
fractional-ái"i irr"t ion of airt also (minor) by
electrolYsis of water'
2O.2 (a) 2HgO '> zÍtg + 02
(b) heating 2Na2O2 +
also 4H9o -> ztlg2c- + 02
2 -or aqueousr 2O2
(c) 2NaNOg -+ 2NaNOz + Oz
(d) 2KC1O3 -> 2KCL + 3oz
(e) zt¡zo *9SE* 2H2o + 02
2 O . 3 ( a ) r * 0 2 + ¡ 9 '
(b ) 2 t ¡a * 02 + Na2O2
(c) 4Li + 02 + 2Lí2O
(d) 2Mg + oz + 2ugo
(e) 4Hg + oz '+ 2lgzo' also 2Hg + oz + 2llgo
( f ) B a * 0 2 + B a O 2
(g) C + Qz + COz' also 2C + Oz -> 2CO
( h ) S + O z + S O z
2 5 + 3 O z + 2 S O g
( i ) 2cueo t oz + 4cuo
(minor Product)
20.6 IA oxides are hard high*me1ting ionic compounds;VIA oxides are gases, l iquids, or low melt ing, and
.. are covalent. IA oxides react hrith water to givebases , V IA ox ides g ive ac ids .
, ' . O . 7 ( a ) O e ( b ) o z @ l O z 2 -2Na2O + 02
+ 2HzO + 4OH + Oz
+ 5Oz + P4Ol 0
+ 10H2O
+ 6HeO + SOz
olr o*
+ + +Tftr TiJr
a-t-
^
olr
++ t+,JI¡t
lT¡k
++ ++ ++ ++1T ?T 1I 1T
+ tTtr Tftr
t+ t+1 T f i
f+
BC*2¡2 unpr.e
+O2
rJñ
BO=fá ; l unpr .e BO=1¡ 0 unpr .e
O2
d *
T *
++ñ
eo:2L¡ I unpr.e
O *
+ + +Tt?t
'lTr<
++U
BO=Iá; 1 unpr .e
r+ +J,II 1T
t+,IT
tTr ¡t
t +1I
( j ) P q + 3 O z + P 4 O e ¡ P +
2O.4 (a ) 2CqHro + 13Oz + BCOz
(b) CsHr 23 + 9O2 + 5COz
(c) 2CgHsO + 9Oz -> 6COz + BHzO
(d) 2ZnS + 3Oe -> 2ZnO + 2SOz
T L 21 1 3
2 -2 0 . 9
2 0 . 1 0
(a) Pb * H2O2 + SO4 + 2H
(b) 2Cr (OH) 3 + 4oH + 3H2O2
(c) 2MnOa + 5HzOz + 6H- ->
(d) AgzO t H2o2 '+ 2Ag + Oz
+ PbSO+ +2 -
+ 2CrO4. L
2Mn * 5Qz
+ H 2 O
2HzO
+ B H z O
+ B H 2 O
r 0 . 1 6 ( a )
( b )
( c )
( d )
( e )
( f )
( a )
( b )
( c )
( d )
( e )
C ¡ 2 H 2 2 O 1 r ( s ) + H 2 S O a ( 1 ) + f Z C ( s ) + 1 1 H z O ( 1 )
+ H2SOa (aq)
N a N O 3 ( s ) + H 2 S O + ( 1 ) + N a H S O q ( s ) + H N O 3 ( 9 )
C u ( s ) + 2 H 2 S o a ( 1 ) + c u s o u ( . q )
* S O z ( S ) + 2 H z o ( I )
z n ( s ) + H z S O + ( a q ) - + Z n S O a ( a q ) + H 2 ( g )
z n S ( s ) + H 2 S O a ( a q ) + Z n S O 4 ( a q ) + H z S ( g )
F e 2 0 3 ( s ) + 3 H 2 S O + ( a q ) - + F e z ( S O + ) s ( a q ) + 3 H 2 O6 o
. / \ , ' "
Bo=L4 , Type ABrE molecule' one unshared pair'
bent shaPe
i
2 O . I I ( a ) - 2 8 5 . 9 k J m o l e - l o f H 2 o
( b ) - 3 3 3 . 3 k J m o l e I
o f H 2 o
General ly reactions with ozone are
than with oxygen'
20 . I2 2gg.5 kJ mole- l
Sulfur Selenium, 4q-fel lel ! .1$
more exothermÍc
underground and melts the sul-fur
w i th the a id o f comPressed a i r '
2 5 + 3 O 2 + 2 S O g
2 - .(aq,)
2 -
. 1 0 . 1 7 ( a ) s + F e + F e s r F e s + 2 H + - > F e 2 + + H 2 s
( b ) S + O z + S O z , S O z + H 2 O + H z S O s
( c ) N a 2 S O 3 ( a q ) + S ( s ) + N a 2 S 2 O 3 ( a q )
( d ) S + O z + S O z , 2 S O 2 t 0 2 + f g Q . ,
N-OH( .q) + SO3 (9) + ¡ ¡aHSOs (aq)
( e ) S + o z + S o z ¡ 2 S o 2 * 0 2 + f g Q r ,
SO3 + H2SOa -> HzSzOt
None of the above answers i-s unique. See forinstance ans\^¡er key in text.
. L B 2 S O 2 + O z + 2 S O s
SO2 + CL2 -> SO2C12
soz (g ) + H2o (1 ) ->
3soz (g ) + C103 +
Soz ( s ) + oH ,^ : , ->t q 9 ,
2 -
20.13 The c rys ta ls o f Sg mel t to a mob i le f lu id bu t i t s
v iscos i ty inc reases w i th fu r ther inc rease in
temperature as Ss r ings open and form Sx chains'
At very high temperatures various fragments boi l off '
S o , S q ¡ S 2 P a r t i c u l a r l Y '
( f ) so2 ( s ) + so3 (aq )
, ^ . , O . i - a - ' d . O\ l 3 /
: : : : : :( b ) n : O : S = O :
s / " I n r: O : V
( c ) , 4 , O. . 1
I,¿, o (6
H 2 S O 3 ( a q )- 2 -
6 O H + 3 S O q + C l + 3 H 2 O
HSog (aq)
+ H 2 O + 2 H S O g
AB2E2 t lpe, bent
AB3E type, tr igonal pyramid
(3 resonance fo rms)
ABa type, tetrahedron
resonance forms)
2O.L4 Hot water is PumPedwhich is forced uP
2 0 . 1 5 ( a ) S + 0 2 + S O z
minor amounts:2 -
+ S ( a q ) + s 22 -
* S O 3 + S z O s
F e + S - ) F e S
S + 2F2 -+ SF+, S * 3F2 -+ 5Pa
23 + CL2 '> SzCIz
S + 4HNO3 + SOz (g) + 4NO2 + 2H2O
/ f \
( s )
a l s o
s ( s )
S ( S )
@ . .
e,,o/o\,
r14 1 1 5
,B ,O, o = l = 0 ,
manv resonance forms
AB4 tlE)e, tetrahedron
(6 resonance forms)
2 O . 2 O ( a ) c H s c ( N H z ) s * H 2 o + c H s c ( N H z ) o + H z S
(b) SO2 + H2O + HeSOs
( c ) S O r + H 2 O + H z S O +
(d) A tesa + 6H2O + 2A1 (OH) 3 + 3HzS (g)
(e ) SeO¡ + H2O + HzSeO¡
( f ) TeOg + H2O + HzTeO+
(S) HzO + HzSOs -> HzOz + H2SOa
(h) HzO + H2S2O7 -> 2HzSO+
20 .2L 3O2 + 2H2S -> 2H2O + 2SO2
3O2 + 2HzTe -> 2HzO + 2TeOz
2 P b s + 3 o 2 + 2 P b o + 2 s o 2
(a1so get higher oxides of Pb)
2 N a 2 S o 3 * 0 2 + 2 N a 2 S o 4
) o . 2 2 2HC1 (aq) f Na2So3 (aq) + 2NaCl (aq) + Soe (g ) + H2o
2HC1 (aq) + Na2S (aq) + 2NaCI (aq) + HzS (g)
Na2S2O3 (_q)
+ 2HC1 (aq) - ' 2NaCl (aq) + Soz (g )
+ H 2 O + S ( s )
Ihe answer key gives the above in ionic form.
. to.23 (a) 45 + 6oH -> 2s2- * s2o32- + 3HzO
(b) s2o32- + 2H+ -> s + soz(s) + H2o
. ' . 0 . 2 4 S O 2 + S + O o - ,2 - ? -
S O g + S z O s -
Note the expand.ed octet in SF4,which. is permissible for S but nocfor O (on ly 2s , 2p orb i ta ls ,max imum of 4 ) .
' .0.26 Per-acids are polymers formed. by removing H2O fromthe simple acid. peroxy-acids have O-O bonds.
' t¡ .2'1 (a) Add eb2+ la1so many other metal-s) to form a darkcolored, very insoluble metal sulf ide. Or add
H- to form foul small ing H2S gas.
(b) Add H* to form sharp snel l ing SO2 gas.
(c) Add 8.2* to precipitate BaSo+. Other metals,
e . 9 . , p b 2 + a l s o u s e d .
(d) Add acid to form H2S 03 (and eventual ly SO2 gas)and S(s) which forms a rnÍ lky col loidal precipitate.
' t r -28 (a ) H2O2 + HOSO2CI + HCI + HOSO2 OOH
(b) HeOe + 2HOSO2CI + 2HCI + HOSO2O - OSO2OH
Structural ly the above reactions are:
(a) no -G\+ñi)-E -o" + Hcl + no-o-8-ou\Y--l ,, ,,
o o o oi l ^ l l
(b) Ho - ó -G\*fu-4r\+lcr)- s - oH + 2Hc1l \/ \1,-- tlo o
o oi l t l
+ H O - S - O - ' O - S - O Hl t l lo o
L L 7
( e )
( a )
( b )( d )
. ' .0 .25 r - 3 - r/ \
F F
oll ll two tetrahedra (each
tÓ - s - S - i l - s - ót n l ike part d) jo ined"
ll l[ " \7 corner to corner '
i \ . ¿i.i l l ll l l l
- ó - s - ó - s - ó - n. - i l " 1 1
I l u
O : O :
ó : ó 'i l l ll l t l
- 6 - ó - o - ó - s - ó - H. . f l 1 1 "
l l l lO : O :
( f )T\^ro tetrahedra (each
l ike part c) sharing
a corner .
Two tetrahedra (like
part c) joined corner
to corner.
I
( a )
(b )
( c )
r-
( d )
I16
ifl
20 .29 (a ) bent , (b ) bent , (c ) t r igona l p lanar '
(d) tr igonal pyramid, (e) tetrahedron'
(f) tetrahedron, (g) distorted tetrahedron or
,,saw-horse,, shape, (h) octahedron, ( i) octahedron
i s soH I . , ,
(b) ComPare(HO) e ,Te 'central atom-
' l . l The e lements become increas ing more meta l f i c as Zincreases, also stabi l i ty of negative oxidation statesdecreases. Mult iple bonding bet\n/een atoms occurs onlyfor nitrogen, and nitrogen is the only one whichcarrnot expand i ts octet. The hydrides becomeincreasingly less basic rn¡i th increasing Z.
N 2 * 3 H 2 + 2 N H s
N2 + 6Li + 2LisN (alsorother Group IA and Group IIAmeta ls . )
N2 r 02 -> 2No high temperature (arc)
N 2 t C a C 2 + C a N C N + C
N2 is so unreactive because the N=N bond has such a- I
high energy, 94L kJ mole -,
about the strongest bondthere is .
Cer ta in c rops , e .9 . , a l fa l fa , con ta in n i t rogen f i x ingbacteria which return nitroqen to the soi l . Othercrops exhaust i t .
Rea l ly pure N2 a t STP' 1 .250 g l i te r - l
"A i r n i t rog€r r " , L .257 g l i te r
In both cases there is hydrogen bonding between theamine hydrogens and the unshared pair on N' but thereare twice as many opportunit ies in ethylene-diamineand more extended and complex H bonded clusters canr e s u l t .
Pa is most reactive because the units of structureare monomeric, the structure is more permeable toreagent, i t has the highest vapor pressure, and mostimportant the 6OaPPP bond angle is greatly strainedand lowers the bond strength. Black phosphorus, th9most complex and highly pol lmerj-c is least reactive.
. I IAPTER 21
. I ' I I I i NONMETALS, PART I I I : T H E G R O U P V A E L E M E N T S
20.30 (a) HTe is a weaker base than.Hs O": iYt : - i '
much larger' (Same reasonang as Hur 4¡¡u
them in the fo rms: (HO)2SO2 versus .
H2SOa has more lone oxYgens on f,ne
I
I
L i
I
I
I
l lB 1 1 9
ff* - = "-4'''
l
Only Pa is soluble' the polymeric forms are noE'
P,+ , a s t r i c t l y mo lecu la r c rys ta l ' i s an e lec t r i ca l
insulatori t tá i" a poorer insulator; and black is
the besc t""á''"I"t plesuma¡ly within the covalent
bonded Planes as ín graPhite'
2L .7 (a ) P+Oo + 6HzO + HsPOs-
PaO5, + BOH + 4HPO3- + 2HzO
PaO6 + H+ - no reaction
Sb+Oe + 6HzO + no reaction
S b a O 5 + 4 O H + 4 S b O z + 2 H z O
sbao6 + 4H+ + AcL -> 4sbocl(s) + 2H2o
Bi2O3 + H2O + no reaction
Bi2O3 + NaOH + no reaction
Bi2O3 + 2H+ + zCL -> 2BiOCl (s) + uzo
r r "o s izoa + 6H+ + 2B i3+ + 3H2o
(very concentrated acid)
2]r.g GraPhite-l ike BN is:
The diamond-l ike BN has each B at the center of a
tetrahedron of N, and vice-versa. To make a modelt
make a face centered cubic ce11 of B atoms, subdivide
it into B sub cubes and put a N into every other sub
cube.
Prepared from the elements (Haber process). An AB3E
type molecule, shaped l ike a tr igonal pyramid. Verypolar. Acts as a base in water solut ion. Pure NH3
has an unusually high boi l ing point (compared to
other Group VA hydrides) because of extensive hydrogen
bonding.
+ +(a) 2NHs (aq) + Ag + Ag (NH3 ) 2
(b) NH3 (ag) + H* +t NH,**
(c ) NH3 (aq) + H2o + co2 -+ NH4 ' + Hco3
(d) 4NH3 (s ) + 3Oz ts l
he- 2Nz (g ) + 6H2o
( e ) 4 N H 3 ( g ) + 5 0 2 ( s ) P t ' h " l t
4 N o ( g ) + 6 H 2 o
( f ) N H 3 ( 9 ) + H C I ( s ) + N H + C I ( s )
( s ) 2 N H s ( g ) + 2 v ( s ) t " t l
z v l l + 3 H 2
( h ) 2 N H s ( 1 ) + 2 N a ( s ) + 2 N a + + 2 N H 2 + H z ( 9 )
Note : Na+ and NHz d isso fve in NH3 (1)
(b )
( c )
N z *
4NH3
3H2 + 2¡¡ntp f
+ 5Oz :; 4NO + 6H2O
+ 02 -> 2NO2
+ H2O + 2HNOa + NO
* 02 as in th i rd reac t ion , e tc .
3Cu + BH+ + 2NO3 * 3Cu2* + 2NO + 4H2O
2NO
3NO2
2NO
( a )
I I\ - - y ' u - n , / " \ N /
N N' i t l l
a B \ r / u \ * / t -
i l lR r - B -
\ n / " u * / \
¡ l
etc. r \^Iith
benzene-l ikeresonance
(a l te rna t ive ly , ge t NO2 in conc . HNO3)
(b) Azn r lon+ + No3 '> 4zn2+ + NH4+ + 3H2O
( c ) P , * O r o , - \ + 4 H N O s ( 1 ) + 4 H P O 3 ( s ) + 2 N 2 O s ( s )( > , ,
( d ) NH3 + HNO3 + NH+NOg
( e ) c a ( o H ) 2 + 2 H N O 3 + C a ( N o s ) 2 + 2 H 2 O
i on i c : ca (oH)z (s ) + zn l + c^2+ + 2H2o
l 1
L20I 2 I
I ' t i
2 I . I 4 ( a ) N e O r N O ¡ N 2 O 3 , N O 2 , N 2 O 4 ¡ N 2 O 5
(b ) NH+Nog h t t l
, " ro + N2o
N2 + 02 tt !
Zono (or burn NHg on Pt)
N O + N O z + N z O g
2 t i o + o z + 2 N O z
2No2 -+ ¡tgu
P + O r o + 4 H N O 3 + 4 H P O s + 2 N 2 O 5
( c )
. ' Ñ = N = ó ' s : N = t l - ó ' ^O ' ^ ' Ó é " e r
,ñ = ó, * l i j = i : (minor form)o @
, ó = ñ - R = U , + : ó = ñ - R - ó ' oo:dr ü'
,ó -Ñ=[ : * :ó=Ñ-ó ' € , f -b=ó, * :ó=B- i "
H - O - - H H - - H
The acj-d hydrogens are only those attached to oxygens.
| . lB (a ) PaOl s + 2H2O + 4HPO3
( b ) 3 P a O 1 e + I O H 2 O - + 4 H 5 P 3 0 ¡ e
( c ) P a O l s + 4 H 2 O + 2 H a P 2 O 7
( d ) P a O l e + 6 H 2 o I 4 H r p o , *
The above formulas represent (a) inf ini te polymer,o r cyc l i c po l lmer , (b ) t r i_mer , (c ) d imer , and(d) monomer . A I l poss i_b i l i t ies a re represented byH P O , for which the reaction would be:n + 2 n 3 n + 1 '
f n+24-
P+or o * - t - H2o + Hn+zPno¡n+r
l . L 9 ( a ) L i g N + 3 H 2 O - + 3 L 1 O H + N H 3
(b) A lN + 3H2O + A l (OH) 3 + NH3
( c ) C a 3 P 2 + 6 H 2 O + 3 C a ( O H ) z + 2 P H a
(d) CaNCN + 3H2O -+ CaCO3 + 2NH3
(e) NC13 + 3H2O + NHs + 3HOCI-
( f ) P C 1 3 + 3 H 2 O + H 3 P O ¡ + 3 H C L
( g ) P C 1 5 + 4 H 2 O + H s P O q + 5 H C t
( h ) H q P z O z + H 2 O + 2 H 3 P O ' +
( i ) 3NO2 + H2O + 2HNO3 + NO
1 ' o ( a ) H 2 l l 2 O 2 = H z O + N 2 O
(b) 2HNO2 = HzO + N2O3
( c ) 2 H N O g = H z O + N 2 O 5
( d ) 2 H a P 2 O 7 = A H z O + P 4 O 1 e
' 1 . 1 7 nIIt l
H - P
f,
ó ttlil
P - ót "I
II
H
I ItlP - Ól "I
II
H
- o H
i
";' .'b.: o" \ @ @ z
I N -N\ many resonance formso ' .o / \ d ' .
a !Á' 'h ' .c r ' Y . .
@ . . @ . / 2 "' N - o - N' many resonance forms
pr' " -.g:tt
N H a N O 3 + N z O + 2 H 2 O
N H 4 N O 2 + N z + 2 H z O
P b ( N O 3 ) z + P b O + 2 N O 2 + Z O 2
N a N O 3 + N a N O 2 + Z C z
2Nal{3 -} 2Na + 3N2, also 3NaN3 -+ NagN + 4N2
2 I . I 5 ( a )
( b )
/ ^ \\ e /
( d )
( e )
z L . r o (a ) 2NH3 + OCl + NzH+ + C l + H2O
(b) 5Hz + 2H+ + 2Noz + 2NHgOH+ + 2H2o
(c) NHI+F + 2HF + NFs + 3Hz
r22 1,23
{${-
| . 2 4 ( a )
( b )
( c )
( d )
( e )
( f )
| . 2 6 ( a )
( b )
( c )
( d )
( e )
( f )
1 . 2 7 ( a )
t \ - ! \/ \
c i s
Na3As + 3HzO + AsH3 + 3NaOH
A s 2 O 5 + 3 H e O + 2 H e A s O +
l4g3Bi2 + 6H2O + 2B iHs + 3Mg (OH)2
A s 4 O 5 + 6 H 2 O + H s A s O a
2SbC13 + 3H2O + SbzO¡ + 6HCl
D u . T " ¿ - D ü - ! ü ' + Il ¡ l + 4 + ! ¡ I J( b ) , ó = Ñ - ó , €
tv
, ó = Ñ - ó , * *
@ " o
( c ) , Ñ = ó t < - > , Ñ =
ool d ) ¡ Ó - N = Ó : +
I\7 1
: O : A.. \7/ñ
.. \y( e ) H - o - { = o ," l
: O : 6" \-,,
tY
: O - N = O :a \ " / ñ\./ \7
ó ,
F ! .
t. - a
N = N- / . . ,
trans
( f ) H - Ñ = N = Ñ : + - + " = f - N = N :
@ o o @2r .22 (a ) l t+ + H2NNH2 + HzNNHg* , 2H+ + HzNNHz + HgNNH¡
(b) u+ + H2NoH + H:NoH-
( " ) u+ + No2 + HNoz¡ 2HNo2 + Hzo + No + No2
(d) H+ + NH3 + NH+*
(e) 2H+ + co32 + Hzo + co2
2 I . 2 3 ( a ) 4 A s + 3 O 2 + 2 A s 2 O 3
(b) P ,+ + 3Oz + P+Oo , P ' * t 5O2 -> P+Or o
( c ) 2 P C l a t O z + 2 P O C 1 g
(d) Oz + 2NO + 2NOz
( e ) 2 S b 2 S 3 + 9 O 2 + 2 S b z O ¡ + 6 5 0 2
NHs AB3E tr igonal pyramid
NHz AB2E2 bent+
PClr+ AB¿* tetrahedron
PC15 ABs octahedron
SbCl5 ABs tr igonal bipyramid
Sb(OH)5 ( ignor ing the hydrogens)ABe octahedron
Reduction of phosphate rods with carbon usingSiOe to form a CaSiO3 slag.
Direct combination of the elements under pressureat moderate temperatures, using a sol id catalyst.
Treat phosphate rock with sulfuric acid.Alternatively make P4 from phosphate rock (part a),b u r n P 4 t o , P 4 O 1 9 ¿ d n d a d d w a t e r t o f o r m H 3 P O a .
Make NH3 by Haber p rocess , burn i t ca ta ly t i ca l l yto NO, combine with 02 and H2O (problem 27.12) toI I N O 3 .
React H2SOa v ' j - th phosphate rock , Ca3 (PO4) 2 .
Reduce As203 with carbon.
@. ^ - \ l
tla i lv o :
/ñ. . \ ? -e )+ - + H - o - N - o :" t l¡ l
o :
i ( b )
( c )
( d )
( e )
( f )
( e ) 4 H e P g O e = 6 H z O + 3 P a O ¡ q
( f ) 4 H g P O g = 6 H z O i P 4 O 5
( g ) 2 H g A s o + = 3 H z o t A s 2 o 5
2 r . 2 L ( a ) ' ó = ñ - ó , O . * - * O : ó - Ñ = ó '
%: ó = N - Ó ¡ < - )
l ^Q ,ó, t7
124 L25
úr
2L.28 (a )
(b )
( c )
( d )
2L .29 (a )
+NH+
H 4 T
As4O5
Sb2O5
Pa¡ tetrahedron, each P
other 3 P 's and has an
3HzPOz3 -
forms a single bond to
unshared Pair '
+ OH + NHs (g) + H2O
3OH + 3H2O + PH3 (g) +
+ l2OH + 6HzO + 4AsO¡
+ 2Na+ + 2OH t 5H2O + 2NaSb(oH)s
(]HAPTER 22
,IHE NONMETALS
I'ART IV: CARBON, SILICON, BORON, AND THE NOBLE GASES
r '¿rbon and S i l i con
. 1 r t forms a nelat ive ion (Ca- and Cz2-) ; has a st rongtendency toward catenation; and forms a gaseous oxide.
. 4
Catenation can occur easi ly because the C-C bond isvery strong; few bonds to C are stronger.
(a) In diamond each C is surrounded tetrahedral ly byC a toms. (c ) In S iC, S i & C a l - te rna te p laces in thediamond structure. (b) In graphite al l C's are sp2and form a continuous plane; there are only weak(London) forces betv/een planes.
Truly ionic carbides contain metal l ic cations andl ¡ - , -
e i ther C ' o r C2- an ions . Cova len t carb ides , l i keSiC, are covalent netlrork crystals, very hard andhigh melt ing. Interst i t ial carbides contain carbonatoms wi-thin a host metal latt ice without greatlychanging the latt ice or the metal l ic character;usually harden the metal.
(a ) HCN(g) hydrogen cyan ide(b) HCN(aq) hydrocyan ic ac id(c) KCN potassium cyanide(d) KOCN potassium cyanate(e) KSCN potassium thi-ocyanate( f ) Fe(CO)s i ron pentacarbony l , o r more fo rmal ly ,
pentacarbonyl iron (O)(g) NaHCOs sodium hydrogen carbonate(h) NazCOs sodium carbonate
( a ) C o ( g ) + c 1 2 ( S ) + c o c r 2 ( 9 )
( b ) C o ( s ) + S ( g ) + c o s ( g )
( c ) 2 C o ( g ) + o z ( g ) - > 2 C o z ( g )
( d ) C o ( g ) + F e o ( s ) + F e ( 1 ) . + c o z ( S )
( e ) 4 c o ( 9 ) + N i ( s ) + n i ( c o ¡ u 1 s ¡
. 2
L
I
pa i r .
( d ) A s i n P 4 O 5 I
in outward
O's around
but attach a fourth
posit ion, comPleting
e a c h P .
oxygen to each P
a tetrahedron of
1l
L26 L 2 7
l ¡
2 2 . 9
( a )
( b )
( a )2 2 . 4
( c )
( d )
( e )
( f )
(s)
" . " . ( " ) + 2HzO(1) + Ca(OH)2 (s ) + Cz[z (g)
A l+Cg ( " ) * 12HrO(1) -+ 3cH+ (g) r 4A1 (OH) s (s )
: N = N : ( b ) O , c = o , @
Q " = * ,
: ó = c = ñ , O * * O , ó - c = N ,
: ' d : c = ' S :
' : . L 2 H g B O g * H 2 O ? g . O * * H 2 B O 3
Represent the above structurally:
B ( o H ) g + H 2 o i H - ( . e ) + B ( o H ) r *
. l ;1 .13 (a ) 4Mg + B2O3 + 3MgO + MgBz, o r
3Mg + B2O3 + 3Mgo + 28 ( l imited ¡ lS)
(b) 2BBra + 3Hz '> 29 + 6HBr (g)
(c ) 2e + N2 + 23¡
(d) Mg + 28 + MgB2
( e ) B F 3 * F + B F 4
( f ) B 2 O 3 + H 2 O + . 2 H B O z ' a n d
B 2 O 3 * 3 H 2 O + 2 H s B O g ' o r 2 8 ( O H ) ¡
( 9 ) e ( o H ) 3 + o H + B ( o H ) a
( h ) B ( o H ) , h t t !
H B o 2 + H 2 o
( i ) 2 B ( o H ) s 5 B 2 o 3 + 3 H 2 o
( j ) 2L iH + B2H6 + 2L iBH+
. l ) .L4 A 3 center bond jo lns 3 a toms by means o f 2 e lec t ronsin contrast to a conventional bond which joins 2 atoms
by means o f 2 e lec t rons .
. ' . a . . L 5 B + H r o
' l ' l re Nob le Gases
r i i , ( h ) z r :ó¡ \ 7 "I
jg ^ : '1: u I - u - \ . 1 - :" l
I
. 1 - 1 . 3 resonance forms
a
l . : \ "
(a ) caco3 ( s ) + s i oz ( s ) + cas io3 ( t ) + coz (g )h a a f
( b ) c a c o 3 ( s ) " " * i c a o ( s ) + c o z ( g )
+ 2 +( c ) C a C O ¡ ( s ) + H ' + C a + H C O 3
caco3 ,^ , + 2H+ * ca2t + H2o + coz(g)t s , ,
OCN + H2O * 2e -> CN + 2OH - '970V
PbO ' l- H2O + 2e + Pb + 2OH - '580V
Yes, i f the upper equation is subtracted the net
v o l t a g e i s - ( - . 9 7 O ) - ' 5 8 0 = + ' 3 9 0 V
Pbo + cN -> Pb + ocN
(a) ' i - {F
2 2 . I T Two BH2 groups have conventional bonds' The B atom
are joined via two bonds using bridging H atoms w
are 3 center BHB bonds- The conventional bonds a
all in the same plane but the bridging bonds li-e
a plane at right angles so that the four bonds to
are roughlY tetrahedral-
/ L \ - r r .\ P / ' L : .
. / : . '\ . . 2
YÁ- / . . \
i 1 / \ : :
t lt l
( c )
AB2E3 l inear
(tr igonal bipyramidal pairs)
AB4E2 square planar
(octahedral pairs)
AB3E tr igonal pyramid
(tetrahedral pairs for I bonds)! e
l-n
B
128 L29
4r-
i
l*
' i i - ó ,
Xe
. F
ó ,t l
. . I I
: O = X et ll l
( d )
( e )
2 2 . L 7 ( a )
( b )
( c )
( d )
( e )
AB5E sguare PYramid
(octahedral Pairs)
F . .
ABu tetrahedron
(There are many other waYS to= o :
draw the Lewis structure usi
single bonds, + formal charge
on Xe, and - formal charge on
0, b\rt al l lead to same resul
fo r the shape. )
CHAPTER 23
METALS AND METALLURGY
I'he l4etal l ic Bond
Visible l ight of al l wavelengths (photons of al lenergies) are absorbed since an almost continuousband of leuels are avai lable; the re-radiat ion ofthese photons gives the metal i ts luster.
The sl ightest energy increase (thermal energy)raises electrons into empty orbitals which pervadethe whole crystal. These highly mobile electronsc o n d u c t c h a r g e ( i . e . , c u r r e n t ) . o r m o m e n t u m ( i . e . ,heat) ¡ v€r! readi ly compared to other sol ids in whichthe movement of ions is necessary for conduction ofeither electr ici ty or heat.
The extension of the molecular orbital ttrroughout themetal crystal is a consequence of the perfect period-ic l t y o f the e lec t r i c po ten t ia l - - i .e - , the per fec t l yregular arrangement of the atoms. At high temperaturethis regular arrangenent is disturbed by vibrat ions ofthe atoms about their latt j -ce points diminish"ing themobil i ty of the electrons. In an intr insic semirconductor the number of charge carr iers (electrons orholes) incr 'eases exponential ly \^r i th increasingtemperature and the conductivity increases directlywith the number of carr iers. Note that for highlydoped semiconductors the concentration of permanentcarr iers far exceeds the intr insic carr iers and thetemperature characterist ics of conductivi ty revert tometa l1 ic .
Conductors have a conduction band which is onlypart ial ly f i l led. with electrons. Insulators andsemiconductors have completely f i l led conductionbands, above which is a forbidden energy zone. Abovethis is an empty band of orbitals. In semiconductorsthe forbidden zone is narrow enough so that a fewelectrons can be promoted thermally up to the emptyband where they are conduction electrons. (See f ig.2 3 . 3 , p . 5 8 9 ) .
(r) O :-bt ó, -'bl O A86 octahedron'
\ ] l ' / '
many' many resonance formEXe
. . / Lt \oq. o: ..9: o
I
l l
x e ( g ) , + r e ( g ) + x e F 2 ( s )
x e ( g ) + 2 T z G ) + X e F q ( s )
x e ( g ) + 3 F 2 ( g ) + X e F e ( s )
X e F e ( s ) t H 2 o ( t ) + 2 H F ( 9 ) + x e o F + ( l )
X e F e ( s ) + 3 H z O ( I ) + 6 H r ( S ) + x o g ( s )
22.L8 The noble gases above Kr have too high an electro-
negativi ty (too high an ionization energy) to react
readi ly with another non-metal ' Only oxygen and
fluorine have a high enough electronegativi ty,to
extract el-ectron density from the completed szp6
^nn€ iar r r ¡ r . ion o f the nob le gases and fo rm cova len ts v r ¡ ! ¡ Y q r s E ¿
bonds.
22.Lg (a) 6¡,tn2+ + 5Xeo3 + gHzO + 5xe + 6Mnoa + 1BH+
( b ) [ M n O q ] = - L 2 O M ' 3 ' 5 9 9 o f X e O 3
London force depends on the dif fuseness
electron cloud. Both Hz and' He have two
but in He they are tightly bound to one
I
22 .20 of theelectrons
posit ive
center; while in Hz the two attract ing nuclei are
separa ted resu l t ing in an e l l ip t i ca l ' more eas i l y
po la r izab le r e lec t ron c loud '
1 3 0I 3 1
23.4 Neighboring atoms contribute atomic orbitals to
encompassing molecular orbitals' In accordance !Úl
the rule t trat there is one m'o' for each a"o" th'
mil l ions of atoms in a crystal share mil l ions of
m.o . ' s , a l l w i th in a t im i ted energy rang ie ' ca l leó"band" because the m.o . ' s must be so c lose in
within the band. Each band subtends an energy
centered roughly at the a.o. energy' A band mad€
from a higher energy a.o. wi l l cover a higher
range and may be completely separated from a
band by a forbidden zonet an energy range in
t h e r e a r e n o m . o - t s a t a l l '
Physical Propert ies, Occurrence of Metals
(b) Ba2+. sr2+, and pbz+ form very insoluble sulfates.
(c) Na' & Mg-' form very soluble salts with the anions
in sea water. A possible exception is M9CO3 but
in neutral sea water most of the COz is HCO3
ra ther than Co32- .
(d ) PbSr B i2S3, and N iS are very inso lub le .
lowetrwhich
, l ' r ,Llurgy
23 .5
¿ 3 . O
outer P electrons.
2 3 . 7 2 . 4 c m
23.8 native metal
oxide
carbonate
sulf ide
halide
sulfate
si l icate
phosphate
(a) The ions , e .g - , Au3+, have such h igh reduc t ion
potentials that any reducing materials in the
environment have reacted with them to reduce them
to the metal l ic state.
Physical ly metals are good conductors of electr ic
mechanically tough, and usually hard and high nel
invariably very high boi l ing. Chemical ly they are
usually good reducing agents (excepting the coinagt
meta ls ) .
Roasting reduces weight, may produce the metal
d i rec t l y (e .9 . , f rom i ts su l f ide) , y ie ld a mix tu re
of oxides more read.ily amenable to chemical puri-
f i ca t ion .
sulf j-des 2ZnS + 3O2 + 2ZnO + 2SO2
C U S + O z + C u + S O 2
carbonates PbCO3 +'PbO + CO2
(a) Froth f loatat ion is a physical process in which
the desired part icles in the crude ore segregate at
the surface of the air bubbles and can be skimmed off
with the froth, leaving the useless mud below the
l iquid surface.
(b) Parkes process. üiquid zinc extracts si lver form
liquid lead and floats to the top where it freezes
and can be l i f ted o f f .
(c ) Mond process . N i ( impure) + Aco(g) + t ¡ i (co) , * (S)
(d) Van Arkel process. zr( impure) + 2fzlg)
- > Z r l 4 ( 9 ) t h e n , z r I 4 ( g ) + z r ( s ) + 2 I z ( g )
( e ) K r o l t p r o c e s s . T i C l a ( 9 ) + 2 M g ( 1 ) + T i ( s )
+ 2utgcLz (L)
(f) r , iquation. An ore containing a native metal is
heated to just above the metal 's melt ing point and
the pure metal poured off '
(g) zone refÍning. An impure ingot is puri f ied by
causing a thin molten section to pass down its length,
concentrating the impurities in the molten portion-
(h) Thermite process: Cr2Oi + 2Al + AlzOg + 2Cr
App l ied a lso to o ther ox ides . € .9 . , Fe2O3 n luoOt -
Pt
M9CO3
HgS
KCl
BaSOa
ZrSiOa
LaPOa
z 3 . Y
132 1 3 3
23-L2 (a) ore i-s a sol id dug out of the ground which
contains an exploitable amount of a metal '
(b) Gangue is the unwanted part of the ore'
(c) Alün is a mixed sulfate containing a group lA
rnetaf and aluminum as cations; usually a hydrat 'o'
(d) An amalgam ís a solut ion of a metal in mer
(or . r i . " t " i= - i f you pre fer ) ; may be so l id o r
(e) Flux i-s 4n oxide (or carbonate) added in smol
to react with an imPuritY oxj-de'
(f) Flux plus impurity yields slag' which separ
as a hot l iquid and cools to a glassy sol id'
(9) Smelt ing is a high temperature chemical ref l
operation in which metals and slags are presenc
ñ i ^ ^ ^ l - - i * . -\ - t I u f > > 9 r v ¡ r ¡ 9
A 1 2 O 3 ( s ) +
Neut ra l i -ze ,
AI (OH) q +
2 A I ( o H ) g ( s )
to remove A1 from Fe:
2oH (aq) + 3H2o '> 2AI (oH) '+ (aq)
and then calcine to remove H2O:
l iqu ids .
2 3 . 1 3 F e 2 O 3 + 3 C O + 2 F e + 3 C o 2
C a O + S i O 2 + C a S i O 3
Caco3 -> cao + Coz
C + 0 2 + C o z
C O 2 + C - t 2 C O
Disso l ve A l2O3
anode : C , .f c t
cathode: 3e
+ A 1 ( o H ) 3 ( s ) + H 2 o
A 1 2 0 3 , _ , + 3 H 2 O ( g )t 5 ,
i n c ryo ly te and e lec t ro lyze, -
+ 2 0 - + C O z ( g ) + 4 e
1 !
+ A t - " ' + a l ( 1 )
l r | Produce Ca(OH)2 f rom CaCO3
CaCO3 + COz (g) + CaO
CaO + H2O + Ca(OH)2, water suspens ion
Precipitate Mg (OH) 2 from sea water2+ . -+
M g ' - + c a ( o H ) z + M i ( o H ) e + c a '
Form MgC12, d ry i t , and e lec t ro lyze
M g ( O H ) z + 2 H C L + M g C 1 z + 2 H 2 O
anode¿ 2CI + CLz + 2e
cathode, Mg2* + 2e + Mg
| | Very ac t ive meta ls (Eo very negat ive) can on ly be
made by electrolysis of the melt. fmportant examples
a r e M g , A I . L i r N a r C a r K .
Meta ls w i th pos i t i ve Eo such as Ag, Cu, Au, and '
others with only sl ightly negative Eo such as Ni and
Cr can be obtained by electrolysis of aqueous
so lu t ions .
'() (a) CuCog is treated hri th aqueous H2SO4 to form
aqueous CuSO4. (b ) CUS can be roas ted to Cu. In
both cases pure Cu is ob ta ined by e lec t ro lys is ; in/ h \ # 1 - � a i m n r r r a C U i S t h e a n O d e .\ v /
C +' I cu ( impure) + cu- ' + 2e a t anode2 +
Cu- + 2e + Cu (pure) at cathode-|.
' fhe anode voltage is insuff icient to form Ag' or3 +
Au so any Ag or Au in the Cu deposits under the
¿rnode as a sLudge.
In both the basic oxygen process and the open rtür
process the main step is the oxidation of t i : : : :
, - Tn add i t ion ' more imPur i t i c lcarbon with oxygen. ln addit ion' mt
removed in the slag. The basic oxygen process l l
fast as pure 02 is forced into the melt from abo
The open- hearth is very slow as a shal low puddJ'o
metal reacts with the hot air above i t '
r " 1 q
23.L6 (a ) UO3 + 2AL + U + AI2O3
(b) 3V2o5 + l0A1 + 6V + 5A l2o3
(c) Tazos + lONa -> 2Ta + 5Na2o
(d) ThO2 + 2Ca + Th + 2cao
( e ) W O g + 2 A 1 + W + A 1 2 O 3
In some cases i t is not a Powerful
agent ; in some cases i t d isso lves
the metal.
enough reducin or al loYs vlf
135
23 .22 4Ag(s) + 8CN + Oz(g) * 2H2O -+ 4Ag(CN)z
Aqueous cyanide in the presence of airsilver into solution, from r¿hich it canby e lec t ro lys is .
23 .23
The Representative Metals
23.24 (a) 2Na + Hz + 2NaH
(b) Na t N2 + no reaction
(c) 2Na * 02 + Na2O2
(d) 2Na + Cle + 2NaCl
( e ) 2 N a * S + N a z S
( f ) I2wa * P4 + 4Na3e
( g ) 2 N a + 2 C ' > N a 2 C 2
(h) 2Na + 2H2O + 2NaOH + H2
(i) 2l¡a + 2NH3 + 2NaNHe + Hz
23.25 Ionization potential reveals that i tremove an electron from Cs than fromthe free gaseous metal atoms. But inenvironment the ionizing tendency ofover that of Cs because of the largereleased when the very small Li+ ion\4rater molecules.
+ 4OH
brings the
(a) Pbco3 -> Pbo + CO2 roasting
P b o + c + P b + c o 1I r ed r r c t i onpbo + CO + pb + CO2 f
- - - - - - - -
(b) 2PbS + 302 + 2Pbo + 2Soz
2 P b O + P b S + 3 P b + S O 2
(also reactions involving sulfate, see ansr^rer
. ' t . 2 7 ( a ) C a * H 2 + g a ¡ ,
(b) 3Ca * N2 + Ca3N2
(c) 2Ca * 02 + lg¿g
(d) Ca + C12 -> CaC12
( e ) C a + S + C a S
(f) oca r p4 + 2Ca3p2
(g) Ca + 2C + CaC2
(h) Ca + 2H2O + Ca (OH) z * Hz
( i ) ca + 2NH3 -> ca(NH) z * Hz
I l .28 I t wou ld requ i re less inves tmentI c +
Ca ra ther than Ca- ' , bu t CaC12Iattice energy than CaCl that itfor the dif ference in ionizationfor the large latt ice energy of
chargie, and (b) smaller size of
of energy to form
has so much greatermore than compensatesenergy. T\¡ro reaSonS
CaCl2 are (a) greater
cu'n, compared to
23.26 Because of i ts verv small size the Li+ ion
resembles u92+ ldiagonal relationship) and conJ
to Na' forms a rather insoluble f luoride, cand hydroxide. Also Li reacts with N2 to form Lland i ts normal oxide is Li2O.
hypothetical Ca- ion.
2 +Be dif fers draÉtica11y from the rest of the groupin having very small size so that elements likÁ o*]rgunand halogen remain covalently bonded rather thanion iz ing .
(a ) 2AI + 3C12 + A12Ct5 (9 )
(note: A1C13 dimerizes in gas phase)
(b) 4A1 + 3Oz -+ 2ALzAs
( c ) 2 A 1 + 3 s + A t 2 S 3
(d) 2AL + Nz + 2AlN
(e) 2A1 + 2OH + 6H2O + 2AI (OH) + + 3He
( f ) 2AI + 6H+ + 2A l3+ + 3H2
¡ l= lL The sur face appears to be ' ,pass iver , , tha t i s reac tsvery slowly. The passivity may be the result of atough impervious f i lm of metal oxide.
is easier toLi when
an aqueousLi ishydrationis surroundEd
136L 5 I
23.32 Elements wil l behave
on the ion to ionic
about 1.5 t imes the
charge. Both Al and
cova len t ch for ides '
similarlY i f the rat io of
rad ius is the same' A13+
s ize o f Be2+ and l '5 t imes
Be are amPhoteric and bothth€
Transit ion Metals and Inner-transit ion Metals
(a) 2 fe + 3Cl2 + 2FeC1g, Cr same
Zn + CL2 -> ZnCLz
(b) 4Fe + 3O2 + 2FezOg ' Cr same
a l s o 3 F e + 2 o 2 + F e 3 O 4
2 Z n + O z + 2 Z n O
(c) Fe + S + FeS, Cr , Zn same
(d) 2Cr * N2 + 2CrN' others no reaction
(e) reactions with very hot steam only
3Fe + 4H2O -> Fe3O4 + 4H2
2 C r + 3 H 2 O + C r 2 O 3 + 3 H 2
Zn * H2O -+ ZnO + H2+ 2 +
( f ) F e + 2 H ' + F e * H z , o t h e r s s a m e
(g) Fe + OH + no reaction
2Cr + 6oH + 6H2o -> 2cr (oH) . t - * 3H,
Zn + zOH + 2H2O + Zn(OH) +2- + Hz
The transit ion metals are much more usefuL structur-a1ly, but are less metal l ic chemical ly speaking.They are usually colored in their salts, capable ofmany oxidation states, and frequently found combinedwith oxygen in the negative ion.
Zr and Hf are very close in size (which is the rule
for periods 5 & 6 beyond Hf) and considerably larger
than Ti. (Genera}ly period 5 elements are much
larger than per iod 4 . )
C r O + 2 H ' - > C r - ' + H 2 O
CrO + OH + no reaction
c r 2 o 3 + 6 H + + 2 c r 3 + + 3 H 2 o
Cr2Os + 2OH + 3H2O -> 2Cr (OH) +
CrO3 * H2O + H2CrO4 or 2CrO3 + H2O -> H2Ct2O7
CrO3 * 2OH -> CrO'+2 i- H2O
23.33 Both AI3+ and s2-
ne i ther i s Present
2 3 . 3 4 ( a )
( b )
( c )
( d )
( e )
\ r ,
/ ^ \¿ J . 5 4 \ 4 , '
(b )
( c )
( d )
( e )
( f )
(s )( h )
1 + - - - ^ - - 2 t - - +A l " ' + H 2 o Z A l o H + H
s ' + H 2 o ? H S + o H2 -
In basic solut i-on where S
alwninrun is converted to
where Al3+ can exist the
ver ! weak H2S'
S n + 2 C L 2 + S n C l 4
S n + 0 2 + S n O z
Sn + 25 -> SnS2' ^ J
s n + 2 H - - > s n " ' +
Sn + OH * 2H2O ->
or Sn + 2OH ->
3sn + Arf + 4Nos
the ampho
In acid solu
t ied uP as tha
hydrolYze so extensivelY that
Lo .tY extent in neutral solu
can ex is t
Al (oH) q
su l fu r i s
H2
Sn (oH) g2 -
SnO2 +
+ 3SnOz
2H2O + 2OH (aq)
+ p b s O 4 + O ¡ ( S )
PbO + H2O ' r OH - ' Pb(OH)e
-> 2PbO + Oz (g)i
+
) -SnS + S ' - + no reac t ion
2 - ^ ^ 2 -S n S z + S + s n 5 3
P b C l z + C I + P b C I g_ 2 -
S n F ¿ + + 2 F + S n F e
* H z
Hz
+ 4NO + ZHzO
2 -+ Pb (OH) oPbOz (s) +
3PbOz (s)
2PbOz (s)
l
l .
l iL
i
l
!. lr
l 3 B 1 3 9
r-
i
(b) 4r,a
(c) 2La
(d) 2r,a
(e) 2r,a
( f ) 2 fa + 6H- ->
23.40
metall ic trait of easy
23 .4L (a ) +0 .0592 V (b ) +0 '770 V
"1.0 M" would give a result that would be
(c) rhere would be no r¡tay to know that +0'788 V
the correct Eo measurement' The use of rrHgtil ¡
t" t ' t" ,R 24
COMPOUNDS
!t, ' t ure of Complexes
I (a) Coordination number is the nrn"nber of atoms in thefirst coordination sphere, i .e., the. number of atomsconnected to the central metal atom.
(b) A l igand is an atom, ion, or molecule attached tothe central metal atom via an unshared electron pair.
(c) A chelate is a coordination complex formed by abidentate or polydentate l igand, i .e., a l igand. withtv¡o or more coordinated atoms in the same molecule orr o n .
(d) Enantiomorphs are two isomers which are alikecxcept that one is the mirror image of the other.
(e) An inert complex has a very slow rate of dis-sociat ion or l igand exchange.
(f) The low spin state of a complex has as many ofi ts electrons paired as possible.
( a ) c o 3 + , ( b ) A u 3 + , ( c ) v o , ( d ) c o 3 + ,
(c ) Co 2+
' l ' ransit ion metals form complexes most readi ly, alsoohhers whose ions are smal_l and highly charged.. Ther¡rost common arrangements of ligands around the centralrrrctá.I are octahedral , tetrahedral , l inear (2 co-,¡rdinate), and square planar.
I . J I I3 , a base, uses i t s unshared pa i r to bond to Ag+,
,ru acid, via an empty orbital on the Ag+. Alter-
rr, t t . ively one can consider the si lver ion in aqueous
, ; , r lu t ion to be ag(u2O)2+. Then the reac t ion is arrtrcleophil ic substi tut ion or base displacementr ( ) . rc t ion , in wh ich the base NH3 d isp laces the basei l , O .
The noble metals have
potentials' associated
they lack the tYPical
an electron.
unusually high ionizatfonwith their small size.
as the correct Eo. For concentrat ion cel lg' l ¡ ' f
Eo is not involved- A calculat i-on for the cel l
described in part (a) and based on a "1'0 Mrl
concentration of rrHg+rr with I electron exc
v,rould give +0-0592 V as the result, and the ao
measurement would be +0.0296 v'
23.42 (a) 2La + 3Clz + 2laCls
-t- 3O2 + 2lazOg
+ 3 5 + L a 2 S 3
+ Nz + 2LaN
+ 6H2O + 2I¿ (OH) 3 + 3H2
2 L a - ' + 3 H 2
l lI
I
23 .43
the chemical propert ies dif fer also'
The inner-transit ion elements dif fer from
with respect to the number of f elect¡e¡5' büf
electrons are not generally involved in chenlo
bonding so there is not much difference betut'A
elements.
r , - = 1 . 2 6 x 1 O - 3 4 2 4 . 6 ' K = I . 3 5 x 1 0 - 3 2
141
E.
140
2 3 . 4 2
23 .43
23.40 The noble metals have unusually high ionization
potentials' associated with their small size. Thuli
they lack the typical metallic trait of easy loss
an electron.
2 3 . 4 L ( a ) + 0 . 0 5 9 2 V ( b ) + 0 - 7 7 0 v
(c) there would be no l^tay to know that +0.788 V iE
the correct Eo measurement. The use of t 'Hg*" "¡"1.0 M" would give a result that would be regarded
as the correct Eo. For concentrat ion cel lst
E" is not involved. A calculat ion for the cel l
described in part (a) and t¡ased on a " l .O M"
concentration of "Hg*" with I electron exchanged
would give +0.0592 V as the result, and the actual
measurement would be +O.0296 V.
| i lA r " tER 24
COMPOTJNDS
|, l- . j ture of Complexes
. | (a) Coordination number is the nr¡nber of atoms in thefirst coordination sphere, i .e.. the. number of atomsconnected to the central metal atom.
(b) A l igand is an atom, ion, or molecule attached tothe central metal aton via an unshared electron pair.
(c) A chelate is a coordination complex formed by abidentate or polydentate l igand, i .e., a l igand witht\n/o or more coordinated atoms in the same molecule ori o n -
(d) Enantiomorphs are t\^7o isomers which are alikeexcept that one is the mirror image of the other.
(e) An inert complex has a very slo\¡/ rate of dj-s-sociat ion or l igand exchange.
(f) The low spin -state of a complex has as many ofi t s e lec t rons pa i red as poss ib le .
r ( a ) c o 3 + , ( b ) A u 3 + . ( c ) v 0 , ( d ) c o 3 + .
(e ) Co 2+
t Transit ion metals form complexes most readi ly, alsoothers whose ions are sma1l and highly charged. Themost coÍunon arrangements of ligands around the centralmetal are octahedral, tetrahedral, l inear (2 co-ordj-nate), and square planar.
I NH3, a base, uses i ts unshared pair to bond to Ag+,
an acid, via an empty orbital on the Ag+. Alter-
natively one can consider the si lver ion in aqueous
so lu t ion to be Ag(H2O)2+. Then the reac t ion is anucleophilic substitution or base displacementreaction, in which the base NH3 displaces the baseH 2 O .
2 4 . 6 ' K = 1 . 3 5 x 1 0 - 3 2
L4t
(a ) 2La + 3Cl2 + 2LaC1s
(b) 4La + 3o2 + 2Lazos
(c ) 2 I¿ + 35 + La2S3
(d) 2La + N2 + 2¡¿¡
(e) 2r,a + 6H2O - ' 2Ia (OH) 3 + 3H2
( f ) 2La + 6H+ + 2La3+ + 3H2
The transition metals differ from each other with
respect to the number of d electrons' and since d
electrons are very much involved in chemical
the chemical propert ies dif fer also.
The inner-transition elements differ from each
with respect to the number of f electrons' but f
electrons are not generally involved in chemical
bonding so there is not much clifference between
elements.
L40
K = I . 2 6 x l O- 3 +
7-
2 4 . 7 ( a )
( c )
( e )
(s )
2 4 . a ( a )
( c )
( d )
t f \\ ¡ ,
( h )
2 4 . 9 ( a )( b )( c )( d )( e )/ 5 \\ ! /
2 4 . L o ( a )(b )( c )( d )( e )( f )
Kz [Rh (Hzo) cl s ]
Na3. [Reo2 (CN) + ]
K¡+ [Ni (CN) +]
l C u ( N H g ) r + l s [ C r C 1 e ] e
V (co) e
lcoCl (Noz) ( t lHs) + l z So+
Na3 [Ag (SzOs ) e ]
I P t C l + ( N H s ) z ]
(b ) l co (NHg) + ( so ¡+ ) ]Nog
(d) lco (wHg ) z (en) e] Clz
( f ) K+ [Ni (cN) 6 ]
(b) zn [Ptc l6 ]
( e ) [ P t ( N H 3 ) r + ] t P t c l g ( N H r )
(S) Ks [AuBr6 , ]
lN i (NH3) o l s [Co (Noz) e ] z
potassiun tetracyanonickelate (O)
potassium tetracyanonickelate ( I I )ammonium pentachloroaquof errate ( I I I)
tetraamminecopper (I I) tetrachloroplat inate (
nitr i topentaammineir idium (II I) chloride
hexaamminecobalt ( I Ir) tetracyanonickelate (I tr ' l
ni tro syltr icarbonylcobalt (o )diammine te trachlorop latinum ( IV )potassium tetracyanoplat inate (O)
hexaamminecobalt ( t I I) hexanitrocobaltate (I I)
sodium dicyanoaurate (I)
Bi s (e thylene di amine ) chloro thi oc yanatocobaLt
chloride
(a) [P t (NHs ) , * (oH) (so4 ) ] oH
(b) tPd (d ipy) (NCS) 2 l
( c ) [ C o ( N H g ) + C l z ] c l . H 2 O
( d ) [ c r ( N H 3 ) e ] l c r ( C z o + ) z ]
Note in compound (d) that i f Cr is 3+ in the cationand 1+ in the anion, then the original ions are +1and -1 and the ions in the isomer are +3 and -3.
F i rs t cons ider a1 l poss ib le coord ina t ion isomers ,then examine each for stereoisomerism.
C o o r d i n a t i o n i s o m e r s a r e ( a = N H 3 ) : [ P t a 4 ] [ P t C l o ] r
I P t a 3 C 1 ] [ P t a C l s ] , [ P t a 3 C 1 3 ] [ P t a C I 3 ] , a n d
[ P t a a C 1 2 ] [ P t C l 4 ] . I n a l f o f t h e s e t h e s i x -
coord ina te P t i s P t ( IV) and is oc tahedra l ; the four -coord i -na te P t i s P t ( I I ) and is square p lanar .
The f irst two above can have no stereoisomers (norany op t ica l i somers) .
F o r [ P t a 3 C 1 3 ] l P t a c l 3 ] t h e r e i s o n l y o n e p o s s i b l ean ion , bu t two ca t ions :
c1 c1
Isomerism of Complexes
24. IL (a ) KFe [Fe (cN) e ]
(c ) cuz [Fe (cN) o ]
2 4 . L 2
a A 1 1
(b ) Fe [Fe (cN) s ]
(d ) KzFe I re (cN) s ]
F o r P t a 4 c l 2anion, but twoother t rans .
None of the
a
PtCl4 there is on ly one poss ib leca t ions , one w i t .h c is C- l ' s and the
last four have optical isomers.
(a ) A is ICo (NHs ) s ( I i zo) C lBr ] Br . H2o
B i s [Co (NHs ) s (Hzo) zc l ] Brz
(b) hydrate isomers
( a ) l c o ( N H 3 ) s ( S o q ) ] N o a
(b) [rvrn (co) s (NCS) ]
( c ) [ P t ( N H 3 ) g c l ] [ P t ( N H 3 ) c l 3 ]
( d ) [ c o ( e n ) z ( H z o ) B r ] B r 2 ' H 2 o
In (c) both Pt are 2+ in both isomers.
(a) There are tt tro geometric isomers, cis or trans aiwhere a = NHs, t = NCS-
cc i s
L42 I43
(b) Set NH3 =
geometricedge (two
a
a andisomers ,of the a
NOz = n. There are two
fac ia l (a I I a a re c is ) o r
are t rans)
n
" nr¿eLar
( c ) S e t N H 3 = a .
i s an op t i ca l
a
c1(d) Only one
a
n edgr
I f bothisomer
a ' s a n d C l r s a r e c i s t
mirror
have e i ther a ts o r C l ' s t rans .
is an optical i
mlrror
The other is trans BrCl
( f )
c1I f NH3 are t rans ,
( e ) If Cl and Br are cis there
i . e . r a d ' 1 P a l r .
C a l I C 2 o r * 2 - = o x t N H 3 = ¿ .only one isomer
a
a
I f NH3 are c is , there is a d, I pai r
nLrror
L44' I
¿ q
r( g ) T h e r e i s a d , 1 p a i r
24 .L7 No op t ica l i somers are poss ib le fo r square p1and neither for tetrahedral i f any two l igandsr L ^ - - - ^L J I E S ¿ i I t I E . L E E N H c = A .
(a ) The th ree poss ib i l i t i es a re t ransa - C l , o r t rans a - Br . (b ) the twoa r e t r a n s C l ' s o r c i s C l ' s . ( c ) S a m e(d) On ly one isomer . See drawinqs on
2 4 . 1 8 The dipole moment of the trans isomer is zerothe Pt - C l bond d ipo les are a t 180" , and l i kewlthe Pt - N bond dipoles. In the cis isomer thePt - N bond dipoles are at 90o and have a resulopposite in direct ion but NOT EeUAL to the resulo f the Pt - C l bond d ipo les , so there is a ne tmolecular dipole momenE.
Noe
r,l_+ng_jAjsmp¿sxee
t -. 'O [N i (C l ¡ ) q ] - has no unpa i red e lec t rons .
lN ic l4 l ' - must have 2 unpa i red .
. l I [Fe (CN) e] -
is low spin, as deduced from the posi-t ion
of CN in the spectrochemical series, whereas
[Fe F6] -
i s h igh sp in . The conf igura t ions fo r
¡ e ( I l - l ) , á d - r o n a r e :3 - ? -
[ F e ( c N ) s ] [ F e F 5 ] -
III
II
miffor
" v J I
possib i l las (b ) .p . 7 5 6 o f
there canthere is I
+ t
+ + t
2 4 . 1 9 I f e i t h e r t h e N O ' s o r C l ' s a r e t r a n sno optical isomer, but for the al1-cis1 p a i r .
+ + + + +
(a) The Cn complex wil lexceeds P, wh i le the H2O
+ -( b ) [ F e ( c n ) e ]
++ ++ t+
be low spi-n because Acomplex is h igh sp in .
l F e ( H 2 O ) G l
++
t t
t t
mirror
I46
(a) The pa i r ing energy must 1 ie be tween 250 and 460
kJ mol -
and a value of 335 has been reported.
(b) Note in the spectrochemical series p 643 that2 -
CzOg induces even less o f a sp l i t t ing than H2O,
s o i f [ M n ( H z o ) o l 3 +
1 " h i g h s p i n t h e n [ M n ( c e o + ) s ] 3 -
must also be high spin.
I47
2 4 . 2 4 t c o ( N H 3 ) 6 1 ' '
+ t
d 7 ,
+lrzott
P=270kJ
Ao .P
2 ¿
¡ c o ( N H r ) 6 1 " '
+ + t + + +
d " , a o t P
(b) ct2*, d4
Low spin High spin
+
(a ) c r3+ d3 , same fo rstrong or weak f ieldl igands
(b) N i2+ d8 , same fo rstrong or weak
(c ) l ¡ i2 * d8 , squareplanar only occurs withstrong f ield l igands
+ + +
t +
l+ ++ r+,1u2 - ' r2
T
t * dxy
I I d .z2
+tl t+ dxz, dyz
as abovef
t+ +v t+
r + + + +
1l,,ou,I
P=2 lOkJ
+ + + + +
( a ) Z n - ' ,¿ 4 . ¿ )
Low spin
+ + + +
+ + +/ ,L
( i )
Low spin
++ ++ ++t+
( c ) N i - '
Low spin
+ +
+ + + + + +
, 1 0Cl
High spin
t + + +
++ +* r+
, i8
High spin
(e) I"k 2+ , d5
Low spin High sPin
( d ) c o 2 + d 7 ,onJ-y strongligands
a s i n ( c )f i e l d
+ + + +
(d ) N i " ' ,
Low spin
+ _
t+ r+ ++
( f ) F e " '
Low spin
+ + + + +
(h ) ,
Iow spin
High spin
High spin
sprn
u + a( r ) K n d r m u s tspin (high f j .eld)dj-amagnetic
r¡+( S ) I r ' d ' , m u s tsp in (h igh f ie ld )ONLY one unpaired
+ + L _
dL1
+ +
t + 1 + +
,5, o
+ t
+ + t + + +
t^
+ +
,¿o
High
+ t
+ + + + f + + +. ,L ?
(e) , d"
Low spin High sPin
A+ +
, o
High
(e ) co2+ d7 , a l l te t rahedraLcomplexes in 4th peÉiod areweak f ield
t+
t+ ++
+ + +
t+ ++
lowbei f
be lowi f
spin
+ + _ + + _<T
( i ) , d "
Low spin High sPin
t i3+ is d r . on ly one e lec t ron , and the hv o f absorbedlight is the measure of Ao. The red-violet transmitted
color is due to absorption of l i_ght in the mÍdd.le ofthe spec t rum, i .e . , g reen. A s t ronger f ie ld l igandcauses absorption more toward the vj-oLet end Leavinqthe red transmitted.
t +I49
' , .s (a) t?!r ' t 2!7-at *ó t ó f
t"l 1!r * rlo * l"l',.6 (a) t3lr" * 22"lna" *
(c) ll"" * i3* . i"
t ¡ ' l 66 r - , , * 66 rn * O, t ,
2g t t -
3 }o t , . _14
(d) 9" * r ] ]* * r ] lc"- r f , o 1 3
, , . r 1 4 - , 1 1 4 ^ . 0(D' 4-7^g
- 48uq
* _le
(d) le + l lFe + l lMn- r z o 2 3
42"-
4^HezRadioactivi ty
2 5 . L Vüithin the nucleus there must be very strongforces, operating within a very short range
(\' 2 x 1O-r 3cm)
. otherwise it would not be Posfor so many posit ively charged part icles, the
to coexist in such close proximity. rt is Postuthat the force originates from the exchange of
betr^reen nucleons. One can make a rough analogy
hydrogen molecule being held together by the
of electrons between the two nuclei.
25.2 (a) l¡ucl ide means a part icular combination of
and protonsr practical ly synonl¡mous with " isotop6¡
except nucl ide is appl ied to nuclei and isotope tO'atoms. (b) A nucleon is a nuclear part icle of
about lu , i .e . , a p ro ton or neut ron . (c ) The c r lmass is the least quanti ty of f issionable matter
wherein the number of neutrons captured exceeds
number of f ission reactions, so that a chain
can occur. (d) A thermal neutron has kinetic
of the magnitude RT per mole (for T = 29BK). l tg
speed is comparable to that of the average
molecule at room temperature. (e) Fission is a
nuclear reaction wherein a large nucleus spl i ts2 much smaller ones (ranging from 4O-60% of the
in weight), along with a few free neutrons (t
3 per f ission) - ( f) Fusion is the joining of tv¡o
small nucl ides into a larger one. (g) A Tra
element has an atomic number larger than 92.
) ' , . J 2 . 6 M e V 2 5 . 8 9 . 4 0 M e V
; l ' , .9 Energy must be 6 .34 - 6 .12 = 0 .22 MeV. Some decays ,those g iv ing a lphas o f on ly 6 .12 MeV, resu l t in an
- 2 L 7excited
-éSOa nucleus. This decays very short ly
thereafter to the ground state tll"t
releasing the
.22 MeV of excitat ion as a y ray.
l ' r . 1 0 6 . 5 6 - 6 . 2 3 = 0 . 3 3 M e V y r a y s . T h e e x p l a n a t i o n i sparal lel to problem 25.9 but involves the excited
' 2restate or -Jlnn.
. , ' ' . 1 1 1 9 . 9 9 9 9 9 u
. " , . 13 3 .52 MeV
= " , . 1 5 3 0 . 9 8 0 6 6 u
! ' , .L7 Electron capture must
2 5 . L 2 1 1 . 0 2 1 6 6 u
25 . I4 3 .42 MeV
2 5 . L 6 2 6 . 9 8 6 7 2 u
be the process.
2 5 . 3 t"t 2ffat*2rrar"i * |""
t"r llar*fl*s * f"t"r rflet * rl7ro, * |"u
o l2nc." * llNi * l.
tur 1l!a"*1!!"s * l"
{c) -fe * tl?"n * r!!na
tur llua * i;Ms *-1"
(d) -ie . i3* * llct
t¡ 'r t-c of Rlrdioactive Decay
" ' . 2 L . 0 0 3 6 5 9
. " . 23 2BB days
- " , .18 Must be e lec t ron capture ,
, ! r ' . I 9 5 0 . 9 4 4 8 u
:" -2O The nucleus captures the closest electron, namely als electron. Vühen a higher energy electron (from oneof the outer orbitals) fal ls into the empty ls orbitali ts loss in energy i-s emitted as an x-ray.
2 5 . 2 2 ' . o O 7 7 4 g
2 5 . 2 4 6 . 4 0 h r . I
151
. E A
150
-al
25 .26
2 5 . 2 7
2 5 . 2 9
2 5 . 3 l
- 1( a ) . 0 0 6 2 4 m i n
- l( a ) . 2 6 6 6 y x
2 5 5 m i n
1 . 5 5 x l o - 6 4 s
( a ) I . 5 5 7 x 1 0 r 7
( b ) 1 . 5 x 1 0 - g
(b) 111 ¡n in
( b ) 2 . 6 0 Y r .
25 .28 2900 Y rs . o l d
2 5 . 3 0 0 . a 2 7 c í
atoms
Nuclear Reactions
Di si 4tegrati,ojl !_eri e s
I 5 4 4 1 5 0 _25.32 *árur -
; ru n -¿¿ot' I (n-llov
o o
I q n
. , b oo+
0- > é +t -
A
r J v m L
b )
l-46 _- ^5mo z
) 2 4^^}(a
) 1 ?- l lPoó q
25.3s t.l !!4. + fn * !1"' n v
tnt ]!n + fn * |"" * 1r"i
t.r lfcr + fn * i" . if'(d) ]"i * in * l" * 7n""
t"r l l !t" + lH + zf" * rf lr
t t r 13c" * | r" ' ' l " * j !s.
(s) '3ltn * aru" * lr, + '33*
(h) '37u * l3*. * a|" + i33*ls.3o t"l 13e n l^" * N" * 1l*
{rl !r,i + ;n * 1". * l"(c) ]"i * ln * ¡" * luu
tal tfc n lrtr * ti* * t
<"t enlv" * l" * |" * l!t.trr 13"' * l* * lH * l:A=
A q A . 1 A p .{s) j ]sc + ;He
'+ lH + ; ; r í
c-'r !]v + fu * zf" * llc.,',.37 t"t 'lZu, (b) '3t^, o 2anl"cr,
(e) "n}u, trl 233u=, rur2f,lv,
l q n* IJ t ¡ +o f ,
l 46e_ +6 ¿
, q ? ? 2 3 2 Í h
9 0 - "
220-^-}(nó o
208- .P h
t5z
25.34 - i imp
9 3 -
) r q
89^"
209^.ó ¿
0 1 5 0 ^ .- e + - , u o-_L O¿l
4 u ^ * 1 4 2 n ^2"" 60."-
228-^ 228^^BB^o 89""
2\6Dn 2L6^tó 4 t J J
¿ J 5 _ Z J J - -
g r P a g 2 u
. . 1 1 1 1z ¿ L _
t s r A f
6 t . r )
209^.B ]
U J
22Brh9 0 ^ "
2 L 2 ^ .R 1
t J J
22911^9 0 - "
2 L 3 _ .83IJA
^^tréJ W
2L3_¿52
)1'7( d ) - ; 3 N p ,
? q n(h ) - : : c f
J Ó
L 5 ¿ 1 5 3
7
? 4 q 1 62 5 . 3 A
- : : c f +
t : N - >v u t
"X" is slmbol
. 133*,element #105
, 1*o*
for
26
CHEMISTRY
cHs
CH
CH¡II
cH3 -
?"toz*íA[
wJ-
@1 5
Nuc]eaI Fission and Fusion
2 5 . 3 9 7 . 5 9 M e V
2 5 . 4 O ( a ) 1 8 0 . 0 M e V r e l e a s e d
(b) . oB18e"
2 5 . 4 I ( a ) 5 . 5 M e V r e l e a s e d
( b ) . 1 e s %
2 ? q I I l ¿ R2 s . 4 2 ( a ) - I i u + l n + 3 i n + * l l c e
Y ¿ U U 5 A
/ < a | | t h(b) - I lu + ln + 3ln + l ln¡ +9 ¿ U U 3 /
(c) ' l lu * ln * g1r, * 134*"Y ¿ 0 "
- O " 5 2 - "
( a ) H
F - ^
, v n z - v B 2 - v n 3
H
C 2 H 5 C H 3
t l- c H - c H - c H 3
u n 3
IC H e - C = C H z
CH - CH3
I
C - C H 2 - C H 2 - C H 3
ur-
ICH - CH3
8 5+ q a
5 1
r3B^^f f
o q+ 11zr
4 U
c1II
II
c1
( b )
( c )
( d )
( e )
( f )
c H g -
U B 2 -
a H -
^ r a = ^u n - u
(s )
Noz
Noz
L54
( h )
---Tl
25.25 (a) .00624 * i r , - r (b) 111- min
25 .26 (a ) . 2666 yx - r ( b ) 2 .60 y r .
25 .27 255 m in 25 ,2A 2900 y rs . o l d
2 5 . 2 9 r . 5 5 x t o - 6 4 u 2 5 . 3 0 0 . 8 2 7 c i
2 5 . 3 1 ( a ) 1 . 5 5 7 x l 0 r 7 a t o m s
( b ) I . 5 x l O s 9
25.3s t"l 3i". * f ' . * ! lu. * y
(b) t3" n 1r, * 1"" * ]"i
t"r ]fcr * ],' * i" . if'(d) ]"i * in * á" * f,""(e) ti!t" * fH * zf" * il! '
rct 23oc" * !^. * |" * l!'.(s) '31*n * |ru * 1r, + '33*
(h) "nZu * i3*. * a|,' * í3!*15.36 (a) t3" * |n"
* | " * 1 l *
ol !r.i * f,, * 1"" * l"(c) ]"i * i" * ¿" * !""(d) '2" , lH * l ]x * y
(e) f,lr" * ln * á" * ?3'"(r) ll"" * lH * ln * l3o"tsr lls" n |nu * !" * llrt(h) ;1r . fH * zf" * Zi"'
,-37 (a) ""2u, (b) 'tt^, o 2f,lcr,
(e) '32u, rrI 2i3"=, (s) ."r2",
Nuclear Reactions
Di si ntegrati g4 !_e_-Li e s
r q ¿ ¿ l 5 n¿ 5 . 3 ¿ - ^ E r + ^ H e + - - D Y
oal z oo
' I 4 ^ n l q n' l ] r ¡ + l . + - l l c a
b f - r o +
1 ¿ " ^ o , * l 4 2 n ^-áit* - ir. 60-.-
) 1 ) 2 2 8 ^2 s . 3 3 - : : r h - I l n a
YV 'JÓ
z ¿ u _ z l o ^^ - K n ^ , P Oticr t +
208^,ó z
) 2 1 2 3 3 p ^25.34 -éárn er^*
2 2 5 n ^ 2 2 L r _g g ^ " B i ' -
29?no '9?"tt 3 ¿ U J
2287.^ 22grhB9^ ' " 90" . .
2 1 6 _ . 2 L 2 _ .^ _ A E ^ - l j a
233r r 229ah92" 90^ "
2 L 7 - . 2 L 3 _ .^ _ A E ^ . I J r( t ) óJ
tlSoo * f. *
t q o 4-;;"u -> )He
+
1 R ñ*" "T1^
146 ^o ¿
z z l _
óó
2L2D^at+
) ) q
9 9
ó¿
( d ) - ; ; N p ,
) \(r( h ) - : : c f
Y Ó
L52I f J
, ( ?a 249. ,F * r5n .1 260- -¿ 5 . 3 ó g 8 " t .
7 r u o n o t *
I O 5 ^ ,
"x'r is slzmbol for element #I05
Nuclear Fi-ssion and Fusion
2 5 . 3 9 7 . 5 9 M e V
2 5 . 4 0 ( a ) t B O . 0 M e V r e l e a s e d
( b ) . 0 8 1 8 ?
2 5 . 4 L ( a ) 5 . 5 M e V r e l e a s e d
(b) .L95"6
2s.42 t"l 23r!rv * fr' * :f" * t33""
u 2llru * 10" * tl" ' 3?*
o 2llru * f'' * s|" * '12'"
CHAPTER 26
ORGANIC CHEMISTRY
( a )2 6 . 7
( b )
( c )
H
ñ - ^
cHs -
c H gIICH
II
Ln2 -
CH¡
¡ u = f
v r ¡ 3
cHg -
. / " n r - C H 2 - C H 3
H
C z H s C H g
t l- C H - C H - C H 3
u n 3
IC H z - C = C H e
C H - C H 3
IC - C H 2 - C H 2 - C H 3
IC H - C H 3
J +
1 ? a
f f
o o+ - - v -
( d )
clIII
u a
( e )
( f )
(s )
Í " ,
o,n-ffrf xo,tV!o,oz
L54
( h )
rMlt ( ) t ( ) l\ / V
1 CI J
2 6 . 2 S e e s t r u c t u r e s p . 7 5 7 .
26.3 Draw the structures inpl ied and then name themcor rec t ly .
(a) CHs - CHz - CH : CH - CHs, by counting from theright a smaller index nunber is requi-red.
- CH3r the longes t cha in i s four
2-mel -hv l h r r f .ane
C - CH3 imposs ib le , 5 bonds oncarbon from left .
- C = CH, by counting from the r ight¡the index numbers are smal
d i (4 \ c l
t r i (5) c l
Ic l - c _ c _ c
II
c1
C1l
c _ c _ c _ c l _II
C 1
l { , . 6 C H 2 = C H - C H 2 - C H s
^ ' n
^ - ñ
cHs
H
^ - ñ
cHs
cHs
/ (Same scheme 2 6 . 5 ¡
butanes (6 st ructures) C1
c1I
I¡C I
c - c - c - c lI
cl-
C1
IC ] - C - C - C C l
?H, -
?'t't l
CH2 - CH2
cHs
IC H 2 = C - C H 3
cHe
C H z - C H - C H 3
chiral-
c1I- c -
carbons* )
- C
I¡cl-
- L
2-pentene
(b) cH2 - cH
t lC H s C H s
( c ) C H 3 - C =
IcHs
( d ) C H 3 - C H
IcHs
1C
IC1II
C]
I- c
cl ct c ll l lt t lr t t
2 - m a { - l r r ¡ l - l - l - ' r r 1J ¡ ¡ ' v e ¡ ¡ f * - - * E . y n e
( e ) C H sI¡
CHs - CH = C - CHg, imposs ib le , 5 bonds on 3 fdcarbon from left .
( f ) CHs - CH - CH2 - CHz - CHs, longes t cha in ia
ón,
IczH s
26.4 (a) a lkenet Crrnr .
s ix carbons .3-methylhexane
(b) alkvnes C H' n 2 n - 2
(c ) a lkad ienes "nnrn_,
(d) cycloalkanes Crr"r '
26.5 Formulas below show only the carbon skeleton and tchlorine; hydrogen was omitted for clari ty.
c lI
m o n o ( 2 ) C l - C - C - C C - C - C
H
a s i n
CII
C?t -
156 r57
c1II
n t - a - r - - r - ¡ t - C
r.1
I
II
cl-
propanes (3
(1
c l - c - c - c - c l
a l a
I - it l
s t r u c t u r e s ) C l - C - C - C
c l - c - c - c - c - c l
c l c lt tt ¡
c - c * - c * - c
II
c1
Br
r^vt'
B r B r - _ B r
r
T
Br2 6 . 9 ( a )
Br../,-*\t ( \ lI t ¡ tv
Br
OH
Noz Q:,
2 6 . 8 ( a )
OH
l'-r\"\?
( b )
OH
,Au'l ( ) l\:l't u'
OHI
rAr srt ( ) tV-
Br
OH
(b ) th ree
Br Br Br
[ñ*o, ñi ñr$u' werpn' Vu
*oz
(c ) one on ly
Noz
OH
r
c1
OH
e' frn'\l
two
A\lu'
rAr"lV,
OH
o,.,.c),.Br
l sB
c1/ \ / \
t ( ) t ( ) tCI
2 6 . L L
Z O . L ¿
z 6 . r 5
^ral.'OO\A\l
crr'
x - C = C - X these four atoms are l inea:r
Each of the carbons which form the double bond must
connect to t \nro unl ike groups.
( a ) C H g Q H ¡\ . /
r - = c N O,/
-\
C H s C H s
( b ) C H s C z H s\ . /'C = C YEs (trans shown), / \H C H 3
( c ) C H s C z H s\ . / \TA
u - !
, / \CHs H
(d) Hoooc ,cooH\ , /\ 'C = C yeS (c is shown)
(c) Cracking is a process in which a long molecule isthermally degraded into shorter molecules without anyother substance involved in the reaction.
(d) A conjugated system has alternating single anddouble bonds.
(e) In an addit ion reaction two molecules are joined
without any other reactant or product involved,usually via one or more double bonds.
(f) In a substi tut ion reaction some atom or groupreplaces the hydrogen attached to a carbon atom.
¿ 6 . I 4 ( a )
r 6 . 1 5 ( a )
,/H
( a ) A n o l e f i n i s a
bond.
(b ) An homologous ser ies i s
the same function dif fering
the nrmber of CHz grouPs in
the molecufe .
H
hydrocarbon contain ing a double
further CHs - CH = CH - CHz -
C H s - C H z - C H 2 - C H 2
v a ¡ 5 v r t z v L L ¿ .
I
CHg -CHz
H z + C H a - C HIIt l
v r r J v . r ¿
CH3 t H2 ->
- cHs
( b )
cHs
H
cHs -
,CH2-CH3./
C = C * H z
\H
C = C - C H z - C H 3 *
a series of compounds wl
from one another onlY ln
( c ) CHr -CHz .
H B r + \ c =
CH3-CH2
cHz
BtrI
v L t z v e r ¡ J
CH 3 -CH2
1 6 0
the hydrocarbon portron
1 6 1
+ l -T f . -
(d ) HBr + CH3 - C = C H + C H s - cHz
l -T{^ -} l -T{^ - a-Rr^ - a-T-I^v a ] J v u L z v ] ¡ J
(a) Br2 + CHa -> HBr + CH3Br
A series of substi tut ions l ike the above takes plaoOlead ing to CH2Br2¡ CHBr3, and CBr4 .
(b) CHs - CH = CH - CH3 * Br2 + CHg - CHBr - CHBrI
ci,
( c ) C H ¡ - C = C - C H 3 + 2 P . 1 2 + C H 3 - C B r 2 - C B r 2
cHs
( d )
.16.19 Substi tut ion on an alkane is dif f icult but can befaci l i tated by a free radical mechanism. An aromaticr ing is most readi ly attacked by a Lewis acid, usuallya posit ive ion. After i t joins the r ing by using apair of "double bond,' electrons, the aromatici ty isrestored by spl i t t ing out H+ from the carbon which wasattacked.
. ' .6 .2O (a) o - and p-n i t ropheno l(b) o- and p-bromophenol(c) m-dinitrobenzene(d) m-bromonitrobenzene(e) m-nitrobenzoic acid(f) o- and p-bromonitrobenzene(S) o- and p-ni_trotoluene(h) o- and p-xylene
i\Lcoholsr Ethers, Carbonyl Compounds,' ' @
' 6 . 2 L ( a )
( b )
arTf ^ - - CHz - CHs same as (c )
II
Br
II
Br
2 6 . 1 6
2 6 . I 7 ( a )
( b )
( c )
Br, * tTlU
tlt l
_ C - H
CH2 = CH2 + Br2 + CH2Br - CH2Br
C H = C H + 2 H B r + C H g - C H B r 2( d ) c H 3
( e j U n 3
U
tlC
- O - C - C H 3t ll l
- O - C H 2 - C H 3
-. v..¿ -^.<r
CHz CHz\ . /
u n - u n
CH2-CH2
, , , ^ H 2 S O ¡ ^ , , / \+ H2O --
; ""rr ./"r,
CH2 - g¡¡
IOH
( f )
f^v+
N a '
(s ) cHsI
C H s - C H z - C H z - C H - C H 2
o
I o -26.L8 (a) In an unslnünetr ical addit ion the hydrogen adds E0
the carbon with the more hydrogens already attached+ ^ i +
(b) The hydrogen, as H-, adds f irst, to form acarbocation. The more stable carbocation has the+ charge on the more substi tuted carbon, so the Hatom goes to the less subs t i tu ted carbon, i .e . , thecarbon wj-th the more hydrogens.
ill l
- C _ O H
L62163
ill t
- c -
(h ) 26.25 Hydrogen bonding leads to very strong intermoLecularfo rces in a lcoho1s.
26 .26 (a ) Gr ignard reagent , C4HeMgBr
(b) NaBr and cyanobutane (n-butyl cyanide)
C+HgCN
(c) Br and n-butyl alcohol (I-butanol)
C + H g O H
(d) NaBr and ethyl n-butyl ether
C a H e O C 2 H 5
26.27 (a ) Hz and C3H7O Na+
(b) HzO and CH3 - CH = CHz
(c) H2O and CH3 - CH - O - CH - CHs
t tCHs CHe
(d ) o
tlH2O and CeHs - C - O - CH - CH3
- lcHs
( e )
C r - ' a n d C H 3
2 6 . 2 8 (a*f) Molecules with double or tr iple:bonds arecleaved to the resultant acids or ketones; aLcohol-sand aldehydes are oxidized to the corresponding acids.
(a) acetic acid and butanoic acid(b) acetic acid and propanone (acetone)(c) 2 molecules of propanoic acid(d) propanoic acid(e) propanone (acetone)(f) propanone(9) p-nitrotoluene is oxidized to p-nitrobenzoic acid(h) too mi ld to c leave, p roduc t i s d io l , 2 ,
3-hexanediol( i) under mild. condit ions reaction stops at aldehyde,
propanal
cHs v L ! z
cHs
( i )
OH
Br
26.22 (a ) 4 -methy l -1 -Pentano l(b) 4-methyl-2-Pentanol(c) 2-methYl-2-Pentanol(d) 2-methyl-3-pentanone(e) ethyl isoProPYl ether(f) 4-methylpentanal(g) methyl PhenYl ketone(h) cyclohexanone(i) methyl benzoate/- i \ *-- i +-obenZOic aCid\ J ¡ ' I r ¡ ¡ ¿ u r v
26.23 Four a lcoho ls and th ree e thers
CaHeOH C2H5 - CH -
IOH
C H ¡ - C H - C H 2 O H
IcHs
C H g - O - C H - C H s
IcHs
v L t z v r ¡ 5
CHs (d , 1 pa i r )
OH
IC H e - C - C H 3
IcHe
C z H s - O - C 2 H 5
t lt lil
C H s - O - C ¡ H z
26.24 (a) methyl propanoate; propyl formate(b) methyl propyl etheri methyl isopropyl(c) propanal(d) 2-butanone(e) 2-pentanol, 3-Pentanol(f) methyl proPanoate
Many o thers a re Poss ib le .
ether
t64 165
26.29 (a ) l -pentano l(b) 2-pentanol(c) pentane(d) f irst 2-pentene' then pentane
26.30 (a ) seo and e thy l b romide
(b) ethane and MgBr2
(c) MaBr and propanoic acid
26.3I (a) (CHg)z CItCOO-l¡a+ sodium 2-methylproPanoate
(b) (cHs) z cH-oH' isopropyl alcohol
(c) ceHz Coo Na- sodium butanoate
(d) CaHz Coo Na+ and Ho-CH2-CH3, ethanol
26 .32 (a ) p ropano l (b ) 3 -hexano l
(c ) 3-methyl-3-pentanol
2 6 . 3 3 ( a ) o H C H s
t t
H2 SOa( c ) 2 C H 3 C H 2 O H 7 + . H z O + ( C H g C H z ) z O
medrum temp.
(d)
( e )
( f )
(s)
( h )
f rom (a) cHc=cHe reduc t ion . ñu^ .H^wTffi-rr-+
un3Ln3
cHgcHzoH strong ox'
> cH3 cooH
CHgCHzOH + HBr + HzO + CH3CH2BT
from (f) CH3-CH2Br*NaCN + CHs-CNz-CN+NaBr
Mg B r * CH3 CHO + CHg-CH-CH-CHs-."
+ (CHs ) zCHCHO /
OH
I+ CH3CH2MgBT + CHg - C - CHz - CHs
ICH¡
from (b) CH3CHO + HCN
o H ot l
cHs-éri-c-o-Na+ strong+ cHa
:id
26.35 CH3CH2CH2OH + HBr + CH3CHzCH2BT
CH3CH2CH2BT + Mg + CHsCHzCH2M9BT
similarly prepare (CH3) 2CHI49Br
OH
I+ C H s - C H
OH
I+ C s H z - C - C H 3
; , ,. u n 3
base- ur\ --_+hydrolysis
OH
I- cH - cooH
(CHg ) z CH
or CH3 Mg Br
( b )
(CHg ) z CO
( c ) HII
v r ¡ J v t t z
II
C H a
C H 3 C H 2 C H - C H 2 - O HII
c H g
^I¡ l
M g B r + C - H - )
H
mr_Id ox .url3Ur12(-r12rjr1 --> L.n3\-n2Lnu
similarly prepare CH3COCH3 (acetone)
(a) CHgCHzCHo + CHgCHzCHzBT - ) (a f te r hydro lys is )
CH gCHeCHOHCHzCHzCHg
(b ) oH
I(CHg)zCH Mg B r + CH3COCH3 + CH3 - CH - C - CH3
I ICHg CHs26.34 (a) cnecnzoH
H'sol Hzo + cH2 = g¡ l t
high temp.( c )
C3HTM9Br + CH3COCH3(b) cHacHzoH *ild o";
cH3cHo (dist.irt the product to
avoid further oxidation)
L66 L67
l
(d ) (CH3)2CHt{gBr * CH3CHzCHO + CH3-CH2-CH-CH-CH3
t lOH CH3
z o . J o
H2 SOaCHgCHzCH2OH --+
high temp.CH3CH = CHz
CH3CH = CHe + HBr + CH3CHBTCHg
cH3cHBrCH3 + NaOH + CH3CHOHCH3 * NaBr
26-37 (a) The alkyl hal ide ionizes to a sl ight, extent togive a hal ide ion and a carbocation which is apowerful Lewis aci.d. that displaces a proton fromwater.
(b) A Lewis base such as a bromide ion displacesthe OH- ion from the alcohol.
(c) HCN ionizes to a sl ight extent and the CNa strong Lewis base, joins the carbon of thegroup. The excess electron is then local_izedoxygen which becomes negatively charged and abase and picks up the hydrogen ion (1eft fromion iza t ion o f HCN) .
Amides
2 6 . 3 8 ( a )
NIH
( b ) CH3NHC2H5
( c ) H 2 N C 5 H 1 2 N H 2
( d )
- NHz
( e )
NO^L
26 .39 P r ima ry am ines ¡
CaHeNH2 (CH3 ) 2CH CH2NH2 (CHg ) g CNHz
C H 3 C H 2 - C H - N H zII
cHe
Secondary amines: C3H7 NH CH3
(C2H5) 2NH (CHs) z CHNHCH3
Ter t ia ry amine (CHg)z NC2H5
26.40 (a ) methy l e thy l amine ' o thers
2 6 . 4 1
(b) one HzNCHzCooH isomer is 2-hydroxyacetamide
HOCHzCONHz. Another is nítroethane C2H5NO2.
(c) N-methyl acetamide CHg - I
- NH - CHs
o
(a) ethylamine CeHsNHz
(b) p - to lu id i -ne , i .e . , p -aminoto luene ' o r
p-methylani l ine
HeN{( )F",V/
(c) HBr and methyl butyl amine
(d ) ot lt l
= n a { - ¡ m i Á a ¡ T ] ^ - C - . N H Z
ion,
on th€stronEthe
Ami-nes
cIo
168 L69
(e) HN+er and CHgCHzCOOH
(f) diethylammonium bromide
(g) base hydrolYsis Yields
( c z H s ) e N H e * B r
CHgCHzCOOH
Pol)¡mers
26"47 (a) Addit ion pol lzmersopens up and joins one(vinyl chloride) is an
are formed when the double bondmolecule to another. Polyexample:
C H z - C H - C H 2 -
Ic1
(h) neutral izat ion yields water' Cl and
ethylamine¡ C2H5NH2
Applied to amines they count the number of carbon
atoms attached directly to the nitrogen. Applied
to alcohols they count the carbon atoms attached
directly to the carbon which carries the -OH group.
(A) CH¡CHBTCH3 * NH3 + CHS - CHCH3 + HBTII
NHz
(b) CzHsCOOH + NH3 + CzHsCOO NH¡+r
(c ) CzHsCOOCH3 + NH3 + CzHsCONHz + CH3OH
(in aqueous medium one gets hydrolysis to- +
CzHsCOO NH+ + CHgOH)
- C H - C H 2 - C H -
t lcl c l
26 .42
2 6 . 4 3
2 6 . 4 4 C H 3 C H 2 O H 2
CHaCHeOH r
26 .45 CH3CH2O ¡
(b) CoBolymers are formed \,/hen two differentunsaturated compounds add. Butadiene-styrenerubber is an example:
¡-CH? - CH = CH - CHn - CH - CH^t| ' "
| ¿ l
r r A ) ri l t ) l I
i repeat unit \2 i
(c) Cond.ensation polymers are formed by condensatj-onreactions, including such compounds as polyesters andpolyamides. Nylon 66 is an example of a polyamide:t ,
H3o* , cH3cooH. H2o
CHsCHzNHz
OH ¡ CH3CH2NH2¡ CH3COO r CHTCHzOH
O Hi l ic - N -
H Ol : ÍN l ' C
II
O Hl l l- c r * H g - c - N
H Ol r I- N ¡ c
II
- c4Hg -- aoEtz -
26.46 (a) The conjugate base of phenol is highly stabi l ized
by resonance (see structures top of page 695) '
(b) The unshared pair of electrons on the nitrogen in
ani l ine is " less avai lable" because i t is withdrawn
into the ring somewhat as suggested by the resonanc€
forms:
repeat unit
26.4A In a Fr iede l -Cra f ts reac t ion the A1C13 is a Lewisacid whi-ch adds a hal ide and generates a reactivecarbocation. In addit ion polymerization AlC13 is aLewis acid which adds to an olef in local izing anegative charge on the AL and generating a carbocationat the other end of the mo1ecu1e, which is propagatedat the end of the growing chain.
26 .49 (a ) E thy lene, o r e thene (b ) te t ra f luoroe thene(c) styrene (phenylethylene, or vinyl benzene)(d) vinyl cyanide (or cyanoethylene, or a-crylonitr i le)(e) adipic acid and 1, 6-diamino-hexane (see problem26.4 '7c) ( f ) i soprene (o r 'methy lbu tad iene)(9) phenol and formaldehyde (h) terephthalic acid
and the ethylene glycol. '
t lI",
a@N*, t
ll"t
fis**"'ñ\ r ' V
L70 L7T
--¡5
2 6 . 5 0cHz
cF2
CH
(a)
(b)
(c )
c 7 d z - c H 2 + c H 2
CF, - CF, r- CF,L L t -
c H 2 - f H t',A''lt ( ) t l\ 7 r
c H ^ - c n +' l lc N l
- cH2-
- cF2-
Amino Acids, proteins
2 7 . L(d) - c}lz -
( e ) S e e 2 6 .
(f) 1-.", -
I
(e)
C = C H - C H o -
J",f c H r -
c H lt lC N I
47 ( c )
C =CH
IcH3
OH
- cH2
cH. ol J I
n - ó H - ¿ -IH
cH. ol J f
H z N - ó H - { ! i
OH
cHz+A
I \ /cfz
(h) I ---., f, fl nf ?lo-.,",-o-'ó{O>bio-c2lt4-o- b<( ))-,-', . u \\__Z \_ /t \ - + r l -
t l
27'2
fl ,,* + flH2N - f r
- b - oH H ' , ' " rñ - cH _ [ - o "CHr-óH-r:r+ \ - |
I
"':
\
cH3-cH-cH3o
o r i+ l l "
H3N - cH - [ - o- H2N - cH - c - o-
, .u- cHr_éu_cH,
cH3-CH_CH3
27.3 There is no chiral carbon atom in glycine so thereis no optical isomerism.
Primary: the sequence of amino acid resid.ues.
Secondary: the local structural_ confj-guration of thec h a i n ( e . 9 . , a l p h a h e l j . x ) .
f", I Í"r flH 2 N - ó - b - u - c H - b - o H
H
O H H T/
repeaü of the above reactionpept ide (shown on page 7Sg).
oH -' H2o +
the dlpept ide. A
gives the tri-
L72 r73
Tert iary: the overal l configuration of the chain;how it is folded.
Quaternary: how several chains (not connected bycovalent bonds) are bonded to form one functj-onalun i t .
Secondary structure depends primarily on hydrogenbonding. Tert iary structure, in addit ion to hydrogenbonding, uses salt formation
+ -/ ñ i r ! '
'
(R-NH3 OOC-R' ) , d isu l f ide l inks (R-S-S-R ' ) ,and van der Waals forces.
1 , o o o , o o o , / l 2 o ! 8 3 3 0 r e s i d u e s
From A and B there are four possible peptides AA,AB, BA, and BB. Note that AB is NOT the same as BA.For tr ipeptides, you can f i l l each of these slots intwo ways: 2 x 2 x 2 = B possible tr ipeptides. Inthe general caser lol l can f i l l each of y slots in x
Vways gj-ving x' possibi l i t ies.
The + sign means that r ight handed rotat ion isobserved for the compound., whereas D slmbolizes theabsolute configuration in accordance with theconvention shown at the top of page 713.
(a) CH3 - CHz - CHz - CH3 vs. CHs - CH - CH3II
cHs
( b ) C z H s - C H - C 2 H 5 v s . C H 3 - C H - C 3 H 7
t lCHs CHa
cH¡ - - OH vs. i ts mirror imaqe
27.LO The chiral carbon is shown by an asterisk.
zHsIc
IH
( e )
t . 5
( a ) H ( b )
IC H g - C * - C O O H
II
UN
HO-CHzCOOH
none possible
f . o
t . 7 (c) CHs - CCIBr - CH¡ none possible
(d) c1 (e )I
C H s - C * - H C H e -
IBr
Carbohydrates
27.LL A carbohydrate is a polyhydroxywith ether, aldehyde, or ketoneformula CH2O¡ or close to it.
Cz Hs
alcohol, frequentlygroups, with empi-r ical
OH
Ic * -I
CN
. B
27.L2 A f ive or six carbon carbohydrate is a monosaccharide,also ca11ed a sugar. An ether formed from two sugarsis a disaccharide. A polyether formed from a sinqletype of sugar (glucose) is a polysaccharide.
II
OH
*- u
II
OH
*
ItOH
2 7 . L 3 C H z -
IOH
2 7 . L 4 C H z -
IOH
The middle carbon is chiral;a d and 1 pair exists.
carbons, 4 J- Somers
one chiral carbon, 2 isomers
( c ) C H e - O - C H 3
(d) t t
1I
** C H - C H O
II
OH 2 chiral
e v r r z
i l li l |
o o Hcf
v s . C 2 H 5 O H
c1. / "
II
OH
L74L75
' a ts and Oi ls
i7 .15 C1 TCOOCH2
ICr zCOOCH
+3NaOH->
C1 TCOOCH2
7 - L 6 C 3 H 6 = C s H h = C 3 H 4 =
C 3 H 6 = C 3 H a = C 3 H 4 =
C 3 H 5 = C s H 4 = C a H + =
Cr zHa 5COOCH2
ICr zHe 5COOCH
ICr zHg 5COOCH2
7 - L 7 C r T H z 3 C O O C H z
ICTTHz3COOCH + 54 /02 +
I
3C1 TCOOT
at r^ - ñHv L t z
t lt lt l
OH OH
CaHr s COOCH2
ICeHls COOCH
u 8 n l S L L J L H 2
39CO2 + 37HzO
Ct I Hz 3COOCH2
7.lB The fatty aeids from whích oi ls are derived areunsaturated.
l .Lg Ibtal of 18 carbons; stearic acid.
rcleic Acids
7.2O An alpha hel ix is a protein conformation; a singlestrand held in place by intrachain hydrogen bonding(approximately paral1e1 to the axis). A double hel ixis a DNA conformationi a double strand held in placeby interchain hydrogen bonding (approximatelyperpendicular to the axis).
' .2I Not identical but complementary. tr{here one chainhas A the other has T, and where one has G the otherhas C.
2 7 . 2 2 Call the two complementary chalns X and Y. Theyseparate and X generates a complementary partner Yrwhich must be identical_to Y, while Y generates acomplementary partner X' rrhich must be identical toX. The two new double hel ixes XYr and YXl, areidentical to the original XY.
27.23 A mutation is a mistake in the sequence of nucleotidesin a DNA chain.
27 .24 90 ,OOO/L2O = 750 amino ac id res idues . I t requ i res3 bases to code one amino acid, so 3 x 75O x 340= 765,000 molecular ! ' ¡ t . RNA.
27.25 (a) complement of A-c-A is U-C-U
(b) complement of U-C-U on DNA is A-G-A
(c) oppos i te 's t rand is T-C-T
Enz)¡mes and Metabolism
27.26 Turnover nrnnber is the number of t imes per minuteone enzl¡me molecule performs i ts catalyt ic function.
27.2'7 Competit . ive inhibj-tors form a complex wi-th enzyme inequil ibr ium with the free species (as does the sub-strate). Non-competit ive inhibitors form permanent(non-reversible) complexes with the enzl¡me.
27.28 If the product of an enzlmatic reaction is a mildlycompetit ive inhibitor i t wi l l " turn-off" the enzymeand prevent it from producing more product than isneeded. The term "feedback" inhibit ion is used whenit is not the primary product i tself but somesubsequent product which competes with the substratefor the enz!¡me and turns off production of the primaryproduc t .
27.29 The enzyme forms a loose complex with the substratewhich causes a particular bond to become d.istortedand made prone to react with minimal energy ofactivation. They are very specif ic because onl-y thecorrect substrate will fit into the template providedl - r r r ' l - l r a
v ¡ ¡ a f I r v
Tt \q
v t L z
I
I
OH
+ 9H2 ->
L76 r77
3 0
3 1
Catabolic means breaking down, and anabolic meansbuilding up or synthesizing.
Suppose a substance A is to be convertedC which has a higher free energy than A.accomplished i f the reaction A + B -) C +negative AG; such a reaction is ca11ed areaction.
to substanceIt can be
ñ L - ^ ^U ¡ ¡ 4 > 4
coupled
3 2 The substance B in the preceding example j_s a "high_energy" molecule. I ts spontaneous reaction to lowenerg:y products can be coupled to a desirable reactionwhich otherwise would be thermodynamically impossible.An example is ATp; in which case "D" represents ADpplus inorganic phosphate.
L t ó