Question

A electrolytic cell similar to that shown in the figure above is constructed. The electronic device shown at the top of the figure is a power supply. One electrode compartment consists of a manganese strip placed in a 1.0 M Mn(NO₃)₂ solution, and the other has a cobalt strip placed in a 0.5 M Co₂(SO₄)₃ solution. The overall cell reaction is:

3 Mn²⁺(aq) + 2 Co(s) 3 Mn(s) + 2 Co³⁺(aq)

(a) Fill in the information necessary to complete the half reactions that occur in the two electrode compartments. Use the lowest-possible whole-number coefficients. To input an ion surround the ion's element symbol with square brackets and put the ion's charge to the right like this: Al³⁺ = [Al]3+ (not [Al]+3), and Li⁺ = [Li]+ (not [Li]1+ or [Li]+1). Do not use brackets for neutral species.

(b) Figure out which electrode is the anode, which is the cathode, the signs on these electrodes, the direction in which the electrons flow through the power supply, and the direction in which cations and anions migrate through the salt bridge and solutions. Use this work to pick all of the statements from below which are true.

Answer 1

Part (a).

Anode half-reaction: Co(s) <----> Co³⁺(aq) + 3e^-

Cathode half-reaction: Mn²⁺(aq) + 2e^- <----> Mn(s)

Part (b).

Statement 3, statement 9, statement 5, statement 8, statement 7 are correct.