Chemistry - A Molecular Science

Chapter 11 Electron Transfer and Electrochemistry

Table 11.1

Standard Reduction Potentials at 25

oC.

OX + ne

1-^

U

RED

oE

(V)

1+K

(aq) + e

1-^

U

K(s)

-2.92

Na

1+

(aq) + e

1-^

U

Na(s)

-2.71

Mg

2+

(aq) + 2e

1-^

U

Mg(s)

-2.36

3+Al

(aq) + 3e

1-^

U

Al(s)

-1.66

2H

O + 2e 2

1-^

U

H

(g)+ 2OH 2

1-(aq) -0.83

Zn

2+

(aq) + 2e

1-^

U

Zn(s)

-0.76

Fe

2+

(aq) + 2e

1-^

U

Fe(s)

-0.44

Best Reductants

2H

O + 2e 2

1-^

U

H

(g)+ 2OH 2

1-(aq)

-0.41

a^

PbSO

(s) + 2e 4

1-^

U

Pb(s) + SO

2- 4

(aq) -0.36

2+Ni

(aq) + 2e

1-^

U

Ni(s)

-0.23

Sn

2+

(aq) + 2e

1-^

U

Sn(s)

-0.14

Pb

2+

(aq)+ 2e

1-^

U

Pb(s)

-0.13

2H

1+

(aq) + 2e

1-^

U

H

(g) 2

0.00

Cu

2+

(aq) + 2e

1-^

U

Cu(s)

+0.34

O^2

(g) + 2H

O + 4e 2

1-^

U

4OH

1-(aq) +0.40

I(s) + 2e^2

1-^

U

2I

1-(aq) +0.54

Fe

3+

(aq) + e

1-^

U

Fe

2+

(aq) +0.77

Ag

1+

(aq) + e

1-^

U

Ag(s)

+0.80

O^2

(g)

+ 4H

1+

(aq) + 4e

1-^

U

2H

O +0.88 2

a^

NO

1- 3

(aq) + 4H

1+

(aq) + 3e

1-^

U

NO(g) +2H

O +0.96 2

Br

(l) + 2e 2

1-^

U

2Br

1-(aq) +1.09

O^2

(g)

+ 4H

1+

(aq) + 4e

1-^

U

2H

O +1.23 2

Cr

O 2

2- 7

(aq)

+ 14H

1+

+ 6e

1-^

U

2Cr

3+

(aq) + 7H

O +1.33 2

Cl^2

(g) + 2e

1-^

U

2Cl

1-(aq) +1.36

MnO

1- 4

(aq) + 8H

1+

+ 5e

1-^

U

Mn

2+

(aq) + 4H

O +1.51 2

PbO

(s) + 4H 2

1+

(aq) + SO

2- 4

(aq) + 2e

1-^

U

PbSO

(s) + 2H 4

O +1.69 2

F^2

(g) + 2e

1-^

U

2F

1-(aq) +2.87

Electron

Free Energy

a. The O

/H 2

O and H 2

O/H 2

half-cell potentials highlighted in yellow 2

are for pure water. They are not the standard reduction potentials because [OH

1-] and [H

1+] are not 1.0 M.

Best Oxidants