Question

Identify the substances being oxidized and reduced: 2 MgO(s) 2 Mg(s) + O₂(g).

a) MgO is oxidized, O₂ is reduced
b) Mg is oxidized, O₂ is reduced
c) MgO is reduced, Mg is oxidized
d) O₂ is oxidized, Mg is reduced

Answer 1

The correct answer is (c) MgO is reduced, Mg is oxidized. Mg changes from an oxidation state of +2 in MgO to 0 in Mg, and O₂ gains electrons, changing from 0 to -2.

Step-by-step explanation:

The correct identification for what is being oxidized and reduced in the reaction 2 MgO(s) → 2 Mg(s) + O₂(g) is that MgO is being reduced to Mg, and O₂ is being oxidized. In this reaction, the Mg in MgO has an oxidation number of +2 and is reduced to metallic Mg with an oxidation number of 0. Meanwhile, the oxygen in O₂ goes from an oxidation number of 0 to -2 in the MgO, which means it is being oxidized. Therefore, the correct answer is (c) MgO is reduced, Mg is oxidized.