Predict anode, cathode, and overall reaction of electrolyzed aqueous solution of salts

Question

Predict the anode, cathode, and overall cell reactions when an aqueous solution of each of the following salts is electrolyzed in a cell having inert electrodes.

a. NaBr

b. CuCl2

c. LiOH

Answer 1

a) NaBr

Cathode: 2H⁺ + 2e- ==> H₂(g)

Anode: 2Br- ==> Br₂ + 2e-

Overall: 2H⁺ + 2Br^- ==> H₂ + Br₂

b) CuCl₂

Cathode: Cu²⁺ + 2e- ==> Cu(s)

Anode: 2Cl^- ==> Cl₂ + 2e-

Overall: Cu²⁺ + 2Cl^- ==> Cu(s) + Cl₂

c) LiOH

Cathode: 2H⁺ + 2e-==> H₂

Anode: 4OH^- ==> 2H₂O + O₂ + 4e-

Overall: 4H⁺ + 4OH^- ==> 2H₂ + 2H₂O + O₂