Question

What is the net reaction for the voltaic cell with Cu/Cu^2+ and Hg/Hg2^2+ half cells?

a. Cu^2+ + 2e- → Cu + Hg2^2+ → 2Hg
b. Cu + 2Hg2^2+ → Cu^2+ + 2e-
c. Cu + 2e- → Cu^2+ + Hg2^2+ → 2Hg
d. Cu^2+ + Hg2^2+ → Cu + 2Hg + 2e-

Answer 1

The net reaction for the voltaic cell with Cu/Cu2+ and Hg/Hg22+ half cells is Cu2+ + Hg22+ → Cu + 2Hg, corresponding to choice d.

Step-by-step explanation:

The net reaction for the voltaic cell with Cu/Cu2+ and Hg/Hg22+ half cells is given by combining the half-cell reactions of each electrode. The reduction half-reaction, which occurs at the cathode, would be for copper:

Cu2+ + 2e- → Cu

And the oxidation half-reaction, which occurs at the anode, would be for mercury:

Hg22+ + 2e- → 2Hg

Coupling these half-cell reactions (with the electrons canceling out), the net reaction is:

Cu2+ + Hg22+ → Cu + 2Hg

This corresponds to choice d.