chuong 2 dien cuc6346

05/03/2015

1

GV: TS MAI TH HI H

Chng 2

CN BNG TRN B MT IN CC

S tch in giao din 2 pha

Trong lng dung dch (1 pha bt k) :

Mi ht (ion/phn t dung mi) chu cc lc tc dng t mi hng nh nhau

Trong 1 th tch dd ln :

Tng vect mmen lng cc ca cc ht = 0 : cc ht khng s u tin sp

xp theo 1 hng no.

Tng in tch ca cc ht = 0.

5-Mar-15 TS. MTHH 2

S nh hng hn lon ca lng cc nc

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S tch in giao din 2 pha

5-Mar-15 TS. MTHH 3

Ti giao din dung dch/pha P (kh, kim loi, thnh bnh cha) :

Lc tc dng ln ht t pha pha P t pha lng dd

Cc ht gn giao din phn b khc trong lng dd : phn t dung mi u tin

quay theo 1 hng, c s tng/gim s ion dng so vi ion m

Phn dd gn giao din tr nn tch in (c d in tch qs)

in trng ca pha dd tc ng ln ht trong pha P :

Nu P = kim loi : electron trn KL c th chuyn v pha/ra xa giao din

B mt pha P tch in

Hiu in th gia 2 pha = bc nhy th

Cu trc ca giao din tch in - Mu Helmholtz-Perrin in tch d trn kim loi thu ht cc ion tri du trong dd li gn b mt :

2 lp in tch d tri du , cng ln nm song song lp in kp

lp in kp t in vi in dung C :

Tm ca cc ion pha dd to thnh mt phng Helmholtz ngoi (outer Helmholtz

plane - OHP)

S gim th gia 2 lp l tuyn tnh

5-Mar-15 TS. MTHH 4

d

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Cu trc ca giao din tch in - Mu Gouy-Chapman

Mt s ion (solvat ha) ri OHP, phn tn xa hn vo lng dd do chuyn ng

nhit. Cng ra xa giao din, mt in tch d cng gim n 0.

Phn in tch d ca dd = Lp khuch tn qd .

Lp khuch tn qd bn in tch qd t cch b mt KL khong cch -1

5-Mar-15 TS. MTHH 5

Cu trc ca giao din tch in - Mu Stern

in tch d qs trong dd chia lm 2 phn :

Phn khng di ng st b mt KL trong OHP : qH

Phn phn tn trong dung dch : qG

2 s gim th :

5-Mar-15 TS. MTHH 6

05/03/2015

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Mt s kiu bc nhy th

Kim loi 1/Kim loi 2 : th tip xc loi 1

Kim loi/Kh : th tip xc loi 2

Dung dch/Kh : th tip xc loi 3

Kim loi/Dung dch in ly : th in cc

Dung dch 1/Dung dch 2 : th khuch tn hay th mng

Ngun gc :

S trao i cc ht in tch gia 2 pha

S hp ph chn lc ion/phn t c cc ranh gii phn chia 2 pha

5-Mar-15 TS. MTHH 7

Khng th o c bc nhy th gia 2 pha bn cht khc nhau

Th in cc - Mt s loi in cc

Cc s pht sinh bc nhy th c ch xy ra trn giao din :

kim loi cht dn in ion in cc

Th in cc = Bc nhy th c c do s chuyn ion, electron thng qua

cc p trn in cc.

Cc loi in cc :

5-Mar-15 TS. MTHH 8

1. in cc loi 1 : lm vic thun nghch vi cation/anion

M(r)|M+

(dd) : M+

(dd) + e M(r)

Ag(r)|AgNO3 (dd)

Pt | H2 (k)|H+ (dd) : 2H

+ + 2e- H2

Pt | Cl2 (k)|Cl- (dd)

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in cc qui chiu (Reference electrode)


c Hydro tiu chun (SHE)

(Standard Hydrogen Electrode)

Pt(r)|H2(k) (1atm) |H+

(dd) (1M)

Qui c : in th = 0 mi nhit

c Calomel bo ha (SCE)

(Saturated Calomel Electrode)

c qui chiu (hay c so snh) : c th c n nh, d lp li; dng lm mc

xc nh cc th in cc khc.

Pin Galvani K hiu pin

c ZnZn2+


c CuCu2+ c Graphite | I-(dd) | I2(r)

c Graphite | MnO4-

(dd), H+

(dd), Mn2+

(dd)

Zn(r)Zn2+(dd)Cu2+(dd) Cu(r) anode (-) cathode (+)

: Ranh gii pha

: giao din khng c th tip xc lng (nh khi dng cu mui)

: giao din c th tip xc lng

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1 2

3 3

L1 L2

ion

B

Sc in ng ca pin Galvani

Khi mch h (dng in = 0, cc giao din trng thi cn bng) :


Tng cc bc nhy th theo 1 vng kn = 0

E + B3 + 32 + 2L2+L2L1 + L11+ 13 + 3B = 0

Vi : B3 + 3B = 0

32 + 13 = 3 - 2 + 1 - 3 = 12

Sc in ng ca pin E c c do cc bc

nhy th :

- Ranh gii gia B v kim loi 3 : B3

- Ranh gii gia kim loi 3 v 2 : 32

- Ranh gii gia kim loi 2 v L2 : 2L2

- Ranh gii gia dung dch L2 v L1 : L2L1

E = 1L1 - 2L2 - 12+ L1L2

Nu b qua th tip xc :

E = 1L1 - 2L2 = hiu 2 th in cc

Zn(r) + 2H+

(dd) Zn2+

(dd) + H2(k)

+1 0 0 +2

P oxi ha kh

Zn 2e Zn2+ : Qt oxi ha Zn

Zn b oxi ha : soh tng 0 +2

Zn l cht kh : cho/mt e

Zn c tnh kh : Zn kh H+

Qu trnh/S oxi ha A (bi B)

A b oxi ha : soh A tng

A l cht kh : cho/mt e

A c tnh kh : A kh B

2H+ + 2e H2 : Qt kh H+

H+ b kh : soh gim +10

H+ l cht oxi ha : nhn e

H+ c tnh oxi ha : H+ oxi ha Zn

Qu trnh/S kh B (bi A)

B b kh : soh B gim

B l cht oxi ha : nhn e

B c tnh oxi ha : oxi ha A

2 cp Ox/Kh

Zn2+/Zn

H+/H2

Bt kh H2 bm trn l Zn

Zn 2e Zn2+

2H+ + 2e H2

Cht kh Cht oxi ha

Cht kh Cht oxi ha


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1. Cu + 2Fe3+ Cu2+ + 2Fe2+

Sa li cc pht biu sai :

A. Cu l dng kh, Cu2+ l dng oxi ha.

B. Ion Fe+3 l cht kh, Fe2+ l cht oxi ha.

C. Cp Ox/kh l Cu2+/Cu v Fe2+/Fe3+

D. Cu c tnh kh v oxi ha c Fe3+

E. Fe3+ oxi ha Cu thnh Cu2+

F. Qu trnh oxi ha Cu2+ (cht oxi ha)

G. Qu trnh kh Fe2+ (cht kh)


Phn ng in cc

Qt oxi ha () Anode

Qt kh (+) Cathode

electron

Cu mui : trung ha in tch 2 bnh cha in cc

Zn2+ i vo dd Cu2+ t dd bm vo thanh Cu

Zn b mn

Cu sinh thm

* Dng in : Cu Zn

* 2 in cc b bin i

Thc nghim :


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2. Pin Zn(r)Zn2+(dd)Ag+(dd) Ag(r)

Chn pht biu ng :

A. Dng in chy t c Zn sang c Ag

B. Dng electron chy t c Zn sang c Ag

C. Khi pin lm vic, Zn b ha tan dn

D. Khi pin lm vic, khi lng thanh Ag tng ln n mt gi tr khng i

E. P trn anode l Zn2+ + 2e Zn

F. P trn cathode l Ag - e Ag+

G. Zn kh c ion bc

Cu trc chung ca pin Galvani


Gm 2 in cc & 2 cp oxi ha kh :

(-) Anode : (Ox1/Kh1) Qt oxi ha :

(+) Cathode : (Ox2/Kh2) Qt kh :

Khi mch h (open circuit) : Sc in ng Epin = th mch h

Khi pin hot ng (phng in) : Epin gim dn

Epin = 0 : khng cn dng e chuyn ng, p trn 2 in cc trng thi cn bng.

Voltaic Cell/ Galvanic Cell Voltage (V)

Pin alkaline (n pin) 1.5

Pin ch-axit ( t) (6 pin 12 V) 2.1

Pin my tnh tay (thy ngn) 1.3

Pin Lithium-ion laptop 3.7

P xy ra trong pin l

t pht c G < 0

Kh1 ne Ox1

Ox2 + ne Kh2

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Cch xc nh cc th in cc theo thang SHE


Cc th in cc c xc nh tng i so vi th c Hydro theo nguyn tc :

Thit lp pin gm :

c Hydro tiu chun H+/H2

c cn xc nh th cn tm

c gi tr Epin cn tm

3. H pin nh hnh v c dng in chy t c Hydro c Zn v Epin = 0,76 V

Tm th in cc km.

4. Pin Pt|H2 (1atm) |H+ (1M) Ag+ (1M)|Ag c sc

in ng 0,8V. Tm th c ca bc.

Th in cc kh Th in cc oxi ha


Qui c : Th c vit ng vi qt kh = Th c kh Ox/Kh

Vd : oZn/Zn2+ = 0,76 V o

Zn2+/Zn = 0,76 V

Kh ne Ox Kh/Ox Th c oxi ha

Ox + ne Kh Ox/Kh Th c kh

Epin = Ox/Kh (+) + Kh /Ox (-)

Epin = Ox/Kh (+) Ox/Kh (-)

Kh/Ox = Ox/Kh

Epin = cathode (+) anode (-)

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+2.87

+1.36

+1.23

+0.80

+0.77

+0.40

+0.34

0.00

0.44

0.83

2.71

Tnh

kh

tng d

n (d

n

h

n

g ele

ctron

)

Tn

h o

xi h

a

tn

g d

n (

d

nh

n e

lect

ron

) F2(g) + 2e

2F(aq)

Cl2(g) + 2e 2Cl(aq)

MnO2(g) + 4H+(aq) + 2e Mn2+(aq) + 2H2O(l)

Ag+(aq) + e Ag(s)

Fe3+(g) + e Fe2+(aq)

O2(g) + 2H2O(l) + 4e 4OH(aq)

Cu2+(aq) + 2e Cu(s)

Fe2+(aq) + 2e Fe(s)

2H2O(l) + 2e H2(g) + 2OH

(aq)

Na+(aq) + e Na(s)

2H+(aq) + 2e H2(g)

Bng th c kh tiu chun ca cp Ox/Kh (298K)

0.74 Cr3+(aq) + 3e Cr(s)

+0.53 I2(s) + 2e 2I- (aq)

0.76 Zn2+(aq) + 2e Zn(s)

+1.08 Br2(l) + 2e 2Br- (dd)

+1.51 MnO4-(aq) + 8H+(aq) + 5e Mn2+(aq) + 4H2O(l)


+0.52 Cu+(aq) + 2e Cu(s)

+0.16 Cu2+(aq) + 2e Cu+(aq)

+0.22 AgCl(s) + e Ag(s) + Cl-

5. Cr(r)Cr3+(dd)Ag+(dd)Ag(r). Pht biu sau ng hay sai :

A. P cathode : Cr3+ + 3e- Cr ; p anode Ag Ag+ + e-

B. P cathode : Ag+ + e- Ag ; p anode Cr Cr3+ + 3e-

C. Eopin = o

Ag+/Ag o

Cr3+/Cr = 0,06V

D. Sut in ng chun 1,54V

6. Graphite | I-(dd) | I2(r)MnO4- (dd), H+ (dd), Mn2+ (dd) | Graphite.

Chn pht biu sai :

A. Ti cathode xy ra s kh : MnO4- + 8H+ + 5e- Mn2+ + 4H2O

B. Eopin = o

MnO4-/Mn2+ o

I2/I- = 0,98V

C. Ti anode xy ra s oxi ha : I2 + 2e- 2I-

D. P trong pin : 2MnO4- + 16H+ + 10I- 2Mn2+ + 5I2 + 8H2O

7. Pin in vi p tng cng sau c E

pin = 1,83V : Br2(dd) + Zn(r) Zn2+

(dd) + 2Br-(dd)

Zn2+/Zn = -0,76V. Gi tr

Br2/Br- l :

A. 2,59V B. 1,07V C. -1,07V D. -2,59V

a.


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Cp c th c ln

hn l cc dng

Tng quan ln - kh nng oxi ha/ kh


Ox2/Kh2 > Ox1/Kh1 :

Cathode (+) : Ox2/Kh2 Ox2 + ne Kh2

Anode (-) : Ox1/Kh1 Kh1 ne Ox1

Ox1 + ne Kh1

Ox2 d nhn e hn Ox1 Kh2 kh nhng e hn Kh1

Kh2 ne Kh1

cng dng dng oxi ha cng mnh, cng d nhn electron

cng m dng kh cng mnh, cng d nhng electron

Ox2 > Ox1 Tnh oxi ha : Tnh kh : Kh2 < Kh1

8. Cho

Fe2+/Fe = - 0,44 V v

H+/H2 . Chn ng :

A. Pin Pt|H2 (1atm) |H+ (1M) Fe2+ (1M)|Fe

B. Pin Fe|Fe2+ (0,1M) H+ (1M) | H2 (0,1atm) | Pt

C. P Fe + H+ Fe2+ + H2

D. H+ c tnh oxi ha yu hn Fe2+


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Nng lng t do ca p trong pin sc in ng

a (tc) b (sp)

G = cng in c ch cc i m pin thc hin c

G = -nFEpin (vit cho bn p c : G = -nF)

Go = -nFEopin (vit cho bn p c : Go = -nFo)

n : s e- cn bng ng vi p c vit

F = 96500 C/mol

E : sc in ng (Volt = Joule/Coulomb)

P trong pin in ha c :

G < 0, Epin > 0 : p t xy ra, pin = pin Galvani

G > 0, Epin < 0 : p khng t xy ra, pin = bnh in phn

G = 0, Epin = 0 : p trn cc in cc ang trng thi cn bng.


9. Tm th c chun ca Cu2+/Cu+ bit th in cc chun ca 2 cp Cu2+/Cu

v Cu+/Cu ln lt l 0,34 V v 0,522 V. (S : 0,158V)

Quy tc Luther :

no = niio

o : th tiu chun ca p tng cng

n : s electron tham gia vo p tng cng

io : th tiu chun ca p trung gian

ni : s electron tham gia vo p trung gian


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Phng trnh Nernst tnh th in cc


P trong pin : a (tc) b (sp)

n = s e trao i cn bng

Epin = Eo

pin RT

nF lnQ

Epin = Eo

pin 0,059

n logQ

aspb

atca

Thng s p : Q =

298K :

G = Go + RTlnQ

Chia 2 v cho nF :

298K :

Ox/Kh = o

Ox/Kh 0,059

n logQ

P in cc : aOx + ne bKh

Th in cc & s ph thuc nng cc cht v thay i theo thi gian.

10. Vit phng trnh Nernst :

a. Cu2+ (dd) + 2e Cu (r)

b. Pt|Fe3+ (dd), Fe2+ (dd)

c. Pt|Cl2 (k) | Cl- (dd)

d. MnO4- + 8H+ + 5e- Mn2+ + 4H2O(l)

khi aMnO4- = aMn2+ = 1 :

f. Ag | AgCl (r) |Cl- (dd)

g. Hg (l) | Hg2SO4 (r) |SO42- (dd). Vit pt theo o

h. Pb | PbCO3 (r), CaCO3 (r) |Ca2+ (dd). Vit pt theo o

i. 3Ag+ + Cr 3Ag + Cr3+

j. Pt|H2 (k, 1 atm) | HCl (dd) | AgCl (r) |Ag

k. Pin nng : M|M+ (a1) M+

(a2)|M


Mn+/M

Mn+/M

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11. Pt|H2 (k, 1 atm) | HCl (a = 0,15) | Hg2Cl2 (r) |Hg. Tm E cho 25oC

oHg2Cl2/Hg = 0,2681

12. H s hot trung bnh ca HBr trong dd nc long 25oC l 0,930 (

5,0 mmolkg-1) v 0,879 ( 20,0 mmolkg-1). Xt c Hydrogen trong dd HBr

25oC hot ng vi p sut 1,15 atm. Tm s thay i ca th c khi nng

axit thay i t 5,0 mmolkg-1 sang 20,0 mmolkg-1 . Chp nhn h s hot

ion m v ion dng bng nhau. (S : 34,2 mV)


Lin h sc in ng nhit

G = H - TS


G

T = - S p

(-nFE)

T = - S p

E

T S =

p nF

E

T p : h s nhit ca s

Bin thin entropi S ca p :

-nFE = H E

T p - TnF

E = E

T p + T

H

nF -

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13. Cho pin Pt|H2 (k) |HBr (dd) | AgBr (r)|Ag v

s Eo (V) = 0,07131 4,99.10-4(T 298) 3,45.10-6(T-298)2

Tm NL Gibbs, entanpi, entropi tiu chun ca p 298 K.


ng dng - Hng s cn bng ca p

Khi h pin ttcb :

G = 0 : E = 0, Q = K = hng s CB


Eopin = RT

nF lnK

= 0,059

n logK Eopin

298K :

K = 10 nEo/0,059

14. Tnh hng s CB ca p trong pin Cu-Zn : Zn|Zn2+Cu2+|Cu

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15. Tm hng s cn bng 298,15K ca 2Cu+ (aq) Cu(r) + Cu2+

16. Tm tch s tan v tan ca AgCl t cc gi tr th in cc 298,15K :


Ag+(aq) + e Ag(s) +0.80

AgCl(s) + e Ag(s) + Cl- +0.22

ng dng - o pH ca dung dch

Nguyn tc :

o s ca pin gm :

c so snh : c Hidro, c Calomen, c Bc clorua

c ch th : c th ph thuc vo pH ca dd cn o, nh c Hidro, c

Quinidron, c thy tinh

1. c Hydro l c ch th :

Pt|H2 (1atm) |H+ (?) KClbh|Hg2Cl2 |Hg

c Hydro : H+/H2 = 0,059lgaH+ = -0,059pH

c Calomen c th x bng thc nghim l : Hg2Cl2/Hg = 0,2438 V

S ca pin : E = Hg2Cl2/Hg - H+/H2 = 0,2438 + 0,059pH

pH =


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2. in cc Quinidron l c ch th :

in cc Quinidron : Pt|Q(dd), QH2(dd), H+(dd)

Quinidron tan t trong nc, p phn ly :

Quinidron (C6H4)2O2(OH)2 Quinon (Q) C6H4O2 + Hydroquinon (QH2) C6H4(OH)2

Cp oxi ha/kh : Q/QH2

Q + 2H+ + 2e QH2

Mch o pH : Hg|Hg2Cl2 KClbhH+(?), Q(dd), QH2(dd)| Pt

E = o quinidron 0,059 pH - cal


Q/QH2 = o

RT

2F ln

aQH2

aQ.aH+2

aQH2 aQ = const

= o + 0,059lgaH+ = o

0,059 pH


3. c thy tinh l c ch th :

Bu thy tinh : nhy vi ion H+ (lm t liti silicat + oxit KL kim)

Giao din bu thy tinh/dd : s trao i ca H+ qua mng thy tinh

bc nhy th :

H+(dung dch) H+ (thy tinh)

(Si-O- + H+ Si-O-H+)

Pha trong bu tt : dd HCl 0,1 M (aH+ = const) : hiu th mng pha trong = const

Bn ngoi bu tt : dd cn o pH c aH+

Th c = hiu s 2 bc nhy th 2 pha ca mng tt

TT = o

TT + 0,059lgaH+

Mch o pH : Ag|AgCl|HCl 0,1 N|thy tinh|dd cn o pHcalomen


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17. Thit lp pin to ra cc p sau, tm sut in ng tiu chun tng ng :

a. Ag+ + Cl- AgCl

b. 2H2(k) + O2(k) 2H2O(l)

c. 2Na(r) + 2H2O(l) 2NaOH(dd) + H2(k)

d. H2(k) + I2(r)2 HI(dd)

e. H3O+ (dd) + OH-(dd) 2H2O(l)

18. Tm p in cc, p pin v sc in ng tiu chun ca pin sau :

a. Pt K3[Fe(CN)6](dd) K4[Fe(CN)6](dd) CrCl3(dd) Cr

b. Pt Cl2(k) HCl(dd) K2CrO4(dd) Ag2CrO4(r) Ag

c. Cu Cu2+(dd) Mn2+(dd), H+(dd) MnO2(r) Pt

d. Pt H2(k) HCl(dd) AgCl(r) Ag

e. Bi Bi2S3(r) Bi2S3(dd) Bi

f. Zn(r) ZnCl2(dd) Hg2Cl2(r) Hg(l)

19. Tm th c chun ca Fe3+/Fe t th in cc chun ca 2 cp Fe3+/Fe2+ v Fe2+/Fe. (S : -0,037V)

20. Tm sc in ng 25oC ca cc pin nng :

a. Ag AgNO3 (0,01m) AgNO3 (0,1m) Ag

b. Ag AgCl NaCl (0,1m) NaCl (0,01m) AgCl Ag

Bit h s hot trung bnh ca dd AgNO3 0,01m v 0,1m l 0,897 v 0,734. Chp nhn h s

hot ca ion dng v m bng nhau.

TS. MTHH 37

21. 25oC pin Cd-Hg CdCl2 0,01m AgCl Ag c sc in ng 0,7585 V. Cho Eo = 0,5732V. Tm CdCl2

trong dd CdCl2 0,01m. So snh kt qu thu c khi tnh ton theo l thuyt Debye-Huckel.

22. Cho : Ag+ + e Ag o = 0,7996V

[Ag(NH3)2]+ + e Ag + 2NH3

o = 0,373V

Tm hng s khng bn ca phc [Ag(NH3)2]+

23. Xt pin Pt H2(k, p) HCl(dd) AgCl(r) Ag. 25oC v nng HCl 0,01m, sc in ng ca pin l

0,4658 V.

a. Vit pt Nernst cho p pin.

b. Tm G ca p

c. Gi s nh lut Debye-Huckel p dng c, tm oAgCl/Ag khi p = 1atm

24. 25oC sc in ng tiu chun ca pin Bi Bi2S3 (r) Bi2S3 (dd) Bi l 0,96V. Tm tch s tan v tan

ca Bi2S3.

25. 25oC v CuSO4 1,0.10-3 m, ZnSO4 3,0.10

-3 m. P Cu-Zn c Go=-212,7 kJ/mol. Tm :

a. Lc ion ca mi dd.

b. H s hot trung bnh ca mi dd in ly

c. Sc tiu chun ca pin

d. Sc ca pin

Cho + = -=

26. Cho pin Ag|AgCl (r) |HCl (dd) | Hg2Cl2 (r)|Hg 25

oC c sd l 0,0465V, h s nhit ca s l

3,39.10-4 V/. Tm lng nhit do pin ta ra hay thu vo.


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27. Tm tch s tan v tan ca Hg2Cl2 t cc gi tr th in cc 298,15K :

Hg2Cl2 +2e2Hg+2Cl- 0,27V

Hg22+ + 2e 2Hg 0,79V

Cho p ha tan : Hg2Cl2 (r) Hg22+(dd) + 2Cl- (dd)

28. Ch c th y Ag ra khi lng vt dung dch Ag+ trong qung ch.

Pb(r) + 2Ag+(dd) Pb2+(dd) + 2Ag(r)

Tm hng s cn bng K v G

298 K ca p ny.

Tm sut in ng ca pin nu bt u vi Ag+ 0,02 M v Pb2+ 0,02 M.

Cho oPb = -0,13V v o

Ag = 0,8V. Chp nhn dng nng thay cho hot .


Hng dn gii BT 17.

a. Ag+ + Cl- AgCl

b. Pt H2(k) H+(dd), H2O(l) O2(k) Pt E

o = +1,23V

H2 - 2e 2H+

4H+ + O2 + 4e 2H2O o = +1,23V

c. Na(r) NaOH(dd) H2(k) Pt Eo = +1,88V

d. Pt H2(k) HI (dd) I2(r) Pt

e. Pt H2(k) H2O(l) H2(k) Pt Eo = +0,83V

2H3O+ + 2e H2 + 2H2O 0,00V

H2 + 2OH- -2e2H2O +0,83V

18.

a. Eo = -1,1V

b. Eo = -1,36 + 0,45 = -0,91V

c. Eo = +0,89V

d. Eo = +0,22 V; 2AgCl(r)+H2(k)2HCl(dd) + 2Ag(r)

20.

a. E=0,059 lg aAg+(0,1m) / aAg+(0,01m) = 0,054V

= +

b. E= 0,055V

21.

E=Eo 0,059.3/2 lga

= 0,5076

Theo D-H : = 0,666


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22.

[Ag(NH3)2]+ Ag+ + 2NH3 K

Ag - e Ag+ o = -0,7996V

[Ag(NH3)2]+ + e Ag + 2NH3

o = 0,373V

Eo= 0,373-0,7996

K=10Eo/0,059 = 6.10-8

23.

a. E=Eo 2RT/F lg(.m/pH21/2)

c. lg = -0,509m1/2 =-0,0509 o = 0,223

24.

2,4.10-98; 1,2.10-20

25.

a. 4.10-3 & 1,2.10-2

b. 0,74 & 0,6

c. 1,102V

d. 1,08

26.

5,26 kJ/mol

27.

2,36.10-18; 8,38.10-7

TS. MTHH 41

chuong 2 dien cuc6346

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