Consider the following reaction:
2 Al(s) + 3 Ni²⁺(aq) → 2 Al³⁺(aq) + 3 Ni(s) E° = 1.410 V
What would be the cell potential at 25 °C as calculated from the Nernst equation if [Ni²⁺] = 0.020 M,[Al³⁺] = 3.60 M?

Question

Quizplus · Accepted Answer

The balanced chemical equation for the given reaction is:
2Al(s) + 3NiS2(aq) → 2AlS3(aq) + 3Ni(s)

The standard cell potential (E°) = 1.410 V.

The Nernst equation is given as:
E = E° - (0.0592/n) log(Q)
Where,
n = number of electrons transferred = 6
Q = reaction quotient = [AlS3][Ni]^3 / [NiS2]^3

At 25 °C, the value of the gas constant (R) = 8.314 J/(mol·K) and the temperature (T) = 298 K.

Substituting the given values in the Nernst equation, we get:
E = 1.410 - (0.0592/6) log(3.60/0.020)^3
E = 1.349 V

Therefore, the cell potential at 25 °C as calculated from the Nernst equation is 1.349 V, which is closest to option D (1.349 volts).

Consider the Following Reaction