CH-1725

Half-equations

Chemistry · Secondary 4 · Medium · Half-equations

Aqueous sodium chloride is electrolysed using inert graphite electrodes.

Which half‑equation correctly represents the reaction at the cathode?

$2H_2O(l) + 2e^- \rightarrow H_2(g) + 2OH^-(aq)$
$2Cl^-(aq) \rightarrow Cl_2(g) + 2e^-$
$Na^+(aq) + e^- \rightarrow Na(s)$
$2H_2O(l) \rightarrow O_2(g) + 4H^+(aq) + 4e^-$

Sign in to check your answer and see the hint and the worked explanation. Free on PrepLab High.

Loading problem…