Calculate Ecell at 25°C for the following voltaic cell. Ksp for NiCO₃ is 1.42 × 10^-7. Ni(s) ∣ Ni²⁺(aq) [sat'd NiCO₃(s) ] || Ni²⁺(aq) (0.010M) ∣ Ni(s)
The half-reaction is: Ni²⁺(aq) + 2 e- → Ni(s) E° = -0.257 V

Question

Quizplus · Accepted Answer

The concentration of Ni²⁺ in the saturated NiCO₃ solution is calculated using Ksp, which is √(1.42 × 10⁻⁷) = 1.19 × 10⁻³ M. Using the Nernst equation, Ecell = E° - (RT/nF)ln(Q), where Q = [Ni²⁺(sat'd)]/[Ni²⁺(0.010M)]. Substituting the values, Ecell = -0.257 V - (0.0257/2)ln(1.19 × 10⁻³/0.010) = +0.0422 V.

Calculate Ecell at 25°C for the Following Voltaic Cell