Question

Which type of half-cell, when used along with a mn/mn2+ half-cell, gives the largest cell potential?

Answer 1

Answer: the options are not given, here are the options.

A. Cu2+/cu

b. Pb2+/Pb

c. Zn²+Izn

d. The potential for all three cells is the same.

The correct answer is A.

Cu2+/cu

Explanation:

A voltaic or galvanic cell is a cell that uses electrochemical energy generate from oxidation reduction reaction to produce electricity.

In this reaction manganese will be the anode and the Copper will be the cathode.

The half-cell reactions are given below and their respective cell potential.

Mn +Mn2+ + 2e- E°=-1.18v

Zn +2e=Zn E°=-0.76v

Pb+ +2r= Pb E° -0.13

Cu2+ + 2e= Cu E° 0.34

In solving the potential of the cell

E°cell= E° cathode -E°anode

For Mn and Cu.

(

s

)

+

Z

n

2

+

(

a

q

)

→

M

n

2

+

(

a

q

)

+

Z

n

(

s

)

E

∘

c

e

l

l

=

−

0.76

V

−

(

−

1.18

V

)

=

0.42

V

For Mn and Pb,

M

n

(

s

)

+

P

b

2

+

(

a

q

)

→

M

n

2

+

(

a

q

)

+

P

b

(

s

)

E

∘

c

e

l

l

=

−

0.13

V

−

(

−

1.18

V

)

=

1.05

V

For Mn and Cu,

0.34-(-1.18) = 1.52V.

Which happens to be the largest among the others.