Under standard-state conditions, which of the following half-reactions occurs at the cathode during the electrolysis of aqueous nickel sulfate at 25^$\circ$C

Question

Quizplus · Accepted Answer

Under standard-state conditions, the reduction potential of Ni2+ to Ni is +0.25 V, while the reduction potential of water to H2 is -0.83 V. Thus, Ni2+ would not be reduced to Ni at the cathode. Instead, water would be reduced to H2. Therefore, choice A and C can be eliminated.
Choice D shows the reduction of Ni2+ to Ni, which does not occur under the given conditions. Therefore, the correct answer is choice B, which shows the reduction of Ni2+ to Ni at the cathode during the electrolysis of aqueous nickel sulfate.

Under Standard-State Conditions, Which of the Following Half-Reactions Occurs at the Cathode