After the stannous chloride solution has been prepared, a few pieces of tin metal, Sn, are dropped into the bottle, to prevent oxidation by air.

Determine the standard cell potential for the following reaction: Sn (s) + Sn4 + (aq) →2Sn2 + (aq)

Express your answer with the appropriate units.

E° = 0.29 V

Explanation:

Let's consider the following redox reaction.

Sn (s) + Sn⁴⁺ (aq) → 2 Sn²⁺ (aq)

We can identify both half-reactions:

Reduction (cathode) : Sn⁴⁺ (aq) + 2 e⁻ → Sn²⁺ (aq) E°red = 0.15 V

Oxidation (anode) : Sn (s) → Sn²⁺ (aq) + 2 e⁻ Ered = - 0.14 V

The standard cell potential (E°) is the difference between the standard reduction potential of the cathode and the standard reduction potential of the anode.

E° = E°red, cat - E°red, an = 0.15 V - (-0.14 V) = 0.29 V