Well, we might as well try a similar question. Magnesium metal reacts with hydrochloric acid to produce hydrogen gas and an aqueous solution of magnesium (II) chloride. What substance is being oxidized.'

Magnesium Mg

Explanation:

Oxidization is the process by which a substance either gains oxygen or losses electrons.

The chemical reaction of the above is denoted by,

Mg(s) + 2HCl(aq) > MgCl2(aq) + H2(g)

Mg went from a 0 to a +2 state which would mean that it lost electrons.

It was therefore oxidized.

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