Answer:
D) Oxygen is oxidized and hydrogen is reduced.
Explanation:
In the electrolysis of water, an electric current passes through an electrolytic solution (e.g. aqueous NaCl), leading to the following redox reaction.
H₂O(l) → H₂(g) + 1/2 O₂(g)
The corresponding half-reactions are:
Reduction: 2 H₂O(l) + 2 e⁻ → H₂(g) + 2 OH⁻
Oxidation: 2 H₂O(l) → O₂(g) + 4 H⁺(aq) + 4 e⁻
As we can see, H in water is reduced (its oxidation number decreases from 1 to 0), while O in water is oxidized (its oxidation number increases from -2 to 0).
