AIIMS 2018 Chemistry Nernst Equation MCQ Question

To calculate the standard cell potential (E₀cell) for the reaction, we use the Nernst equation:

$E = E° - \frac{RT}{nF} \ln Q$

where $E° = 3.17 \, \text{V}$, $n = 2$ (the number of moles of electrons transferred), and $Q$ is the reaction quotient. Given the concentrations, $Q = \frac{[\text{Mg}^{2+}]}{[\text{Ag}^+]^2} = \frac{0.20}{(0.001)^2} = 200000$. Substituting the values into the Nernst equation yields an E₀cell of approximately 3.33 V, confirming option C as correct.

Options A (2.63 V), B (3.01 V), and D (3.51 V) are incorrect as they do not accurately reflect the calculated potential based on the provided standard reduction potential and concentration values.