Examine the unbalanced electrolytic reaction and its two half-reactions.

Cd2+(aq) + Br2(g) → Cd(s) + Br–(aq)
E0 = –1.49 V
Half-reactions:
Cd2+(aq) + 2e– → Cd(s)
Br2 (g) → Br–(aq) + e–
What is the balanced form of this reaction?

Cd2+(aq) + 2Br2(g) → Cd(s) + 4Br–(aq)
E0 = –1.49 V

3Cd2+(aq) + 2Br2(g) → 3Cd(s) + 4Br–(aq)
E0 = –1.49 V

2Cd2+(aq) + Br2(g) → 2Cd(s) + 4Br–(aq)
E0 = –1.49 V

Cd2+(aq) + Br2(g) → Cd(s) + 2Br–(aq)
E0 = –1.49 V

1 answer

What is your problem in answering this. The answer looks obvious to me. AND I note this this half cell is not balanced. Balance that, make sure the electrons lost equal electrons gained and you will know which of the molecular equation is correct.