Question

A standard galvanic cell is constructed in which a H⁺ | H₂ half cell acts as the cathode. Which of the following statements are correct?

Hint: Refer to a table of standard reduction potentials.
(Choose all that apply.)
a. Zn²⁺|Zn could be the other standard half cell.
b. Ag⁺|Ag could be the other standard half cell.
c. As the cell runs, anions will migrate from the H⁺|H₂ compartment to the other compartment.
d. The cathode reaction is H2 -> 2H⁺ + 2e⁻.
e. In the external circuit, electrons flow from the H⁺|H₂ compartment to the other compartment.

Answer 1

In a standard galvanic cell with a H+ | H2 cathode, the reduction half-reaction at the cathode is 2H+ + 2e- → H2, the cathode is where reduction occurs, and in typical galvanic cells, it is positive, while the anode is negative.

Step-by-step explanation:

For a standard galvanic cell where a H+ | H2 half cell acts as the cathode, the answers to your questions are as follows:

1. Half-reaction at each electrode: At the cathode where reduction occurs, the half-reaction is 2H+ + 2e- → H2. If the other electrode were, for example, Zn/Zn2+, then the anodic half-reaction would be Zn → Zn2+ + 2e-.
2. Cathode and anode identification: The H+ | H2 half cell is the cathode because here reduction takes place, and the other metallic electrode would be the anode where oxidation occurs.
3. Electrode polarity: In a galvanic cell, the cathode is typically the positive electrode while the anode is negative due to the direction of electron flow from anode to cathode.