Question

Two half cell reactions of an electrochemical cell are given below :
MnO–4(aq) + 8H+ (aq) + 5e– → Mn2+ (aq) + 4H2O (I), E° = + 1.51 V
Sn2+ (aq) → 4 Sn4+ (aq) + 2e–, E° = + 0.15 V
Construct the redox equation from the two half cell reactions and predict if this reaction favours formation of reactants or product shown in the equation...​

Answer 1

At anode : [Sn

2+

(aq) → Sn

4+

(aq)+2e

−

]×5

At cathode : [MnO

4

−

(aq)+8H

+

(aq)+5e

−

→ Mn

2+

(aq)+4H

2

O(l)]×2

Cell reaction :

_____________________________________________________________________

2MnO

4

−

(aq)+5Sn

2+

(aq)+16H

+

(aq)→2Mn

2+

(aq)+5Sn

4+

(aq)+8H

2

O(l)

______________________________________________________________________

E

cell

∘

=E

cathode

∘

−E

anode

∘

=1.51V−0.15V

=1.36V