Question

The values of standard potentials of the half cells, Sn²⁺ | Sn and Ni²⁺ | Ni are -0.14V and -0.23 V respectively. Calculate the equilibrium constant at 298 K temperature.

Answer 1

★With reference to Standard Electrode Potentials at 298K Sn undergoes oxidation and Ni undergoes reduction.

★The metal undergoes reduction which have more negative E° reduction value when compared to Standard hydrogen Electrode.

★ The half cell equations are

★ At cathode

Ni(2+) +2e- ---→ Ni. E°(reduction)=0.23

★ At anode

Sn---→Sn(2+) +2 e-. E°(anode)=0.14.

★Applying Nerst equation at 298K

E(cell)=E°(cell)–(0.059logQ)÷n

n= number of electrons participated in the redox reaction.

Here n=2

★At equilibrium E(cell)=0

Now substituting values in Nerst equation we get

Q(equilibrium constant)=1/e³.