Question

(i)Oxidation number of oxygen in peroxides is always -------​

Answer 1

Oxidation number of oxygen in peroxides is always -1 .

Because , Oxygen almost always has an oxidation number of −2, except in peroxides.

A peroxide is a molecule which includes −O−O−, like hydrogen peroxide, HOOH.

In hydrogen peroxide, the overall charge is 0, so all the oxidation numbers must add up to 0. The oxidation number for hydrogen is always +1, so

HOOH=0=1×2+X×2

where X is the oxidation number for oxygen.

From this, we can deduce that X=−1.