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The Modern Periodic Table

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1. Read the assinged textbook sections before lecture. 2. Attend lecture; be prompt and alert. =) 3. Download and review the lectures after each lecture.

(when the material is fresh). Study ALL additional slides in the Powerpoint

labeled At Home Practice! And, struggle to work the problem before peeking a the solution.

You may see these ?s again on quizzes/exams.

4. Work all HW problems and other material posted on Polylearn. You may also see questions these again.

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Cu2+ SO42-

NH4+

Fe (II)

NH3 deca

2.8

Chem127(( ( ( ( (((((TOP$IONS$TO$KNOW$ $ $$$$$$$$$$$$$$$$Dr.(Jordanides((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((

*ELEMENTS(in(GROUP(1A((1+),(2A(2+),(3A(3+),(5A(3E),(6A(2E),(and(7A((1E)(follow(the(ion(trend(shown(in((()(and(dont(require(memorization,(just(understand(the(trend.(**These(usually(form(the(cation(specified.(Oxanions(with(four(possible(anions.((Know(how(to(get(the(other(three.(For(example:(perchlorate=ClO4- ,(chlorate=ClO3-(,(chlorite=ClO2- ,(hypochlorite=ClO- . Lastly, practice naming oxoacids.$

aluminum Al3+ nickel(III) or nickelic Ni3+ dichromate Cr2O72-

ammonium NH4+ potassium K+ fluoride F- barium Ba2+ rubidium Rb+ hydride H- cadmium Cd2+ silver Ag+ hydrogen phosphate HPO42

- calcium Ca2+ sodium Na+ hydroxide OH- cesium Cs+ strontium Sr2+ iodate IO3- chromium(III)** Cr3+ tin (II) or stannous Sn2+ iodide I

- cobalt(II) or cobaltous** Co

2+ tin (IV) or stannic Sn4+ nitrate NO3-

copper (I) or cuprous Cu+ zinc Zn2+ nitrite NO2

- copper (II) or cupric Cu2+ acetate CH3COO

- nitride N3- hydrogen or proton H+ arsenate AsO4

3- oxalate C2O42- iron (II) or ferrous Fe2+ bromide Br

- oxide O2- iron (III) or ferric Fe3+ bicarbonate HCO3

- permanganate MnO4- lead(II) or plumbous Pb2+ bisulfate HSO4

- peroxide O22- lead(IV) or plumbic Pb4+ borate BO33

- phosphate PO43- lithium Li+ bromate BrO3- phosphite PO33- magnesium Mg2+ carbonate CO32- phosphide P3- manganese(II)** Mn2+ chlorate ClO3- sulfate SO42- mercury (I) or mercurous Hg22+ chloride Cl

- sulfite SO32- mercury (II) or mercuric Hg2+ chromate CrO42

- sulfide S2- nickel(II) or nickelous Ni2+ cyanide CN

- thiocyanate SCN-

Al2O3 2 x +3 = +6 3 x -2 = -6

Al3+ O2-

Ca1Br2

1 x +2 = +2 2 x -1 = -2

Ca2+ Br -

starting w/ the ions

starting w/ the ionic compound...

Writing Formulas for Ionic Compounds Q: What salt forms from aluminum and oxygen?

Q: What ions are present in CaBr2?

2.6

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Chemical Nomenclature 1. IONIC COMPOUNDS (METAL + NONMETAL)

name cation (charge in Roman Numerals, if variable) name anion

BaO barium oxide

KNO3 potassium nitrate

2.8

Cr2S3 chromium(III) sulfide

CuCl2 CuCl3

NOTE: Common (older) naming system: -ous and ic

cuprous chloride cupric chloride

Which of the following chemical names could refer to more than one common compound? A) calcium hydroxide B) iron bromide C) sodium sulfide D) lithium nitrate E) all of the above refer to more than 1 compound

FeBr3 FeBr2

2.8

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Chemical Nomenclature 2. BINARY COVALENT COMPOUNDS (NONMETALS)

prefix, name of 1st element, prefix, name of 2nd element (with ide ending)

CO2 carbon dioxide

2.8

N2O5 dinitrogen pentoxide

EXCEPTIONS: H2O, NH3, H2O2, CH4 (+organics)

Table 2.6 Greek Prefixes Number Prefix Number Prefix Number Prefix

1 mono-

2 di-

3 tri-

4 tetra-

5 penta-

6 hexa-

7 hepta-

8 octa-

9 nona-

10 deca-

Name P4O10 (a) tetraphosphorus decaoxide (b) fourphosphorus nonaoxide (c) tetraphosphorus decoxide (d) Tetraphosphorus decoxide

(c) omit a of a prefix if the element begins in an o

2.8

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3. NAMING ACIDS (hydrogen + other nonmetals in water) A) binary acids: hydro, name of anion with ic ending

2.8

HF(aq) hydrofluoric acid B) oxoacids: (acid with H, O, and another element)

+ [O]

-[O]

-[O]

OXOACIDS OXOANION

ClO3- chlorate

ClO4- perchlorate

ClO2- chlorite

ClO- hypochlorite

HClO3 chloric acid

HClO4 perchloric acid

HClO2 chlorous acid

HClO hyprochlorous

acid

3-11

IO4- is the periodate ion. How would you name IO2-? A) hypoiodite B) periodite C) iodate D) iodite -2 [O]

-1 [O]

does not exist

-3 [O]

2.8

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Stoichiometry of Formulas & Eqns.

Chapter 3

Some images have Copyright The McGraw-Hill Companies, Inc.

1 Mole of:

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mole (mol) - amount of a substance that contains as many elementary entities as there

are atoms in exactly 12.00 grams of 12C

1 mol = NA = 6.0221367 x 1023

Avogadros number (NA)

Dozen = 12

Pair = 2

The Mole (mol): A unit to count numbers of particles

6.022 x 1023

3.1

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Molar mass - the mass of 1 mole of in grams eggs shoes

marbles atoms

Elements: atomic mass (amu) = molar mass (grams)

Example: M of Li = 6.941 g/mol

M = molar mass unit, g/mol

Compounds: sum of atomic masses of ALL elements Example: M of CO2 = 1 M C+ 2 M O

= 12.0 + 2(16.0)=44.0 g/mol 3.1

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Mass-mole-number

relationships

Figures 3.2/3.3 3.1

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x 6.022 x 1023 atoms K

1 mol K =

How many atoms are in 0.551 g of potassium (K) ?

0.551 g K 1 mol K 39.10 g K

x

8.49 x 1021 atoms K

g M" " mol NA" " atoms

M = molar mass in g/mol NA = Avogadros number 3.1

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How many H atoms are in 72.5 g of C3H8O ?

M) 1 mol C3H8O = (3 x 12) + (8 x 1) + 16 = 60 g C3H8O

NA) 1 mol H = 6.022 x 1023 atoms H

5.82 x 1024 atoms H

mol ratio) 1 mol C3H8O molecules = 8 mol H atoms

72.5 g C3H8O 1 mol C3H8O 60 g C3H8O

x 8 mol H atoms 1 mol C3H8O

x 6.022 x 1023 H atoms

1 mol H atoms x =

g C3H8O M" " mol C3H8O mol ratio" " " mol H atoms NA" " Hatoms

3.1

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340 g 1 mole C12H22H11 4.2 g table sugar x

nHow many oxygen atoms is there in 1 teaspoon (~4.2 g) of table sugar, C12H22O11 ?

1 mole C12H22H11

6.022x1023 molecules C12H22O11 x

1 molecule C12H22O11

11 oxygen atoms x

= 8.1 x1022 O atoms in table

sugar

Lecture Question

A) 8.1 x 1022 O atoms

B) 7.4 x 1021 O atoms

C) 1.2 x 10-2 O atoms

D) 2.8 x 1025 O atoms

Molar mass = 12 x12g/mol + 22 x 1.0g/mol + 11 x16g/mol =340g/mol (I rounded, but use 4 sig.figs. on atomic masses )

3.1

g sugar M! ! mol sugar mol ratio! !! molecules sugar NA! ! Oatoms

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Mass % of an element in a compound =

n x molar mass of element molar mass of compound x 100%

n = # of moles of the element in 1 mole of compound

C2H6O

%C = 2 x (12.01 g) 46.07 g x 100% = 52.14%

%H = 6 x (1.008 g) 46.07 g x 100% = 13.13%

%O = 1 x (16.00 g) 46.07 g x 100% = 34.73%

52.14% + 13.13% + 34.73% = 100.0% ethanol

3.1

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Is it possible to de

termine a

formula of an unkn

own?

Empirical Formula -simplest (lowest integer # of atoms) Ex. hydrogen peroxide, HO

Molecular Formula -actual # of atoms Ex. hydrogen peroxide, H2O2

3.2

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Empirical Formula

Ex. Determine the empirical formula of a compound that has the following percent

mass: K 24.75 %, Mn 34.77 %, O 40.51%.

nK = 24.75 g K x = 0.6330 mol K 1 mol K

39.10 g K

nMn = 34.77 g Mn x = 0.6329 mol Mn 1 mol Mn

54.94 g Mn

nO = 40.51 g O x = 2.532 mol O 1 mol O

16.00 g O

3.2 K0.6330Mn0.6329O2.532

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K : ~ ~ 1.0 0.6330 0.6329

Mn : 0.6329 0.6329

= 1.0

O : ~ ~ 4.0 2.532

0.6329

KMnO4

3.2

K0.6330Mn0.6329O2.532

Empirical Formula cont.

The mass percent of an oxoacid of sulfur is : 1.75 % H, 56.14 % S, 42.11 % O. Determine the empirical formula.

3.2

nH = 1.75 g H x = 1.736 mol H 1 mol H

1.008 g H

nS = 56.14 g S x = 1.751 mol S 1 mol S

32.07 g S

nO = 42.11 g O x = 2.632 mol O 1 mol O

16.00 g O

H : =1.0 1.736 1.736

S : 1.751 1.736

~ 1.0

O : ~ ~ 1.5 2.632 1.736

H1S1O1.5multiply subscripts by 2 to get integers H2S2O3

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24 3.2

How To Experimentally Determine Molecular Formulas! 1. Determine the empirical formula & the empirical

molar mass (MM). 2. Calculate: M of compound = whole-number

M empirical formula 3. Molecular formula = multiply the whole-number

by subscripts in the empirical formula. Example: A compound was determined to have an empirical formula

of CH2. Its molar mass was determined to be 42.12 g/mol. What is the molecular formula for this compound?

1. CH2, MM(CH2) = 14.03 g/mol 2. 42.12 g/mol ~ 3

14.03 g/mol

3. Molecular formula is (CH2)3 or C3H6.

A compound was found to contain 53.31 % C, 11.19 % H and 35.50 % O. It's experimental molar mass is 90.12 g/mol. Determine the empirical and molecular formula of this compound.

A) CHO, C2H2O2 B) C2H5O, C4H5O C) C2H5O, C4H10O2 D) C5H2O, C10H4O2 E) C2H2O, C4H4O2

the empirical formula = C2H5O1MM of C2H5O1 = 45.0607 g/mol

step2 : calculate the ratio = experimental MMempirical MMratio = 90.12 g/mol45.06 g/mol 2

molecular formula = 2 C2H5O1 = C4H10O23.2

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g CO2 mol CO2 mol C g C

g H2O mol H2O mol H g H

g of O = g of sample (g of C + g of H) = 11.5 g (6.0 g C + 1.5 g H) =

11.5 g of ethanol is combusted. Collect 22.0 g CO2 and 13.5 g H2O

6.0 g C = 0.5 mol C

1.5 g H = 1.5 mol H

4.0 g O = 0.25 mol O

Empirical formula C0.5H1.5O0.25

Divide by smallest subscript (0.25) Empirical formula C2H6O 3.2

How To Experimentally Determine Empirical Formulas!

Review for Tues.