A solution of nickel sulphate in which nickel rod is dipped is diluted 10 times. the reduction potential of Ni at 298 K

Options

(a) decreases by 60 mV
(b) decreases by 30 mV
(c) decreases by 30 V
(d) increases by 30 mV

Correct Answer:

decreases by 30 mV

Explanation:

Let the initial concentration of Ni²⁺ = a. Since the solution is diluted 10 times, its concentration = a/10. Applying Nernst equation, E = E⁰ – 0.0591/2 log a /a/10. E = E⁰ – 0.030(log 10) ⇒ E = E⁰ – 0.030. Therefore the reduction potential of Ni decreases by 30 mV.