Question

The oxidation number of oxygen in peroxides is __.

• A. -1
• B. -2
• C. +1
• D. 0

Hint:

The oxidation number of oxygen in peroxides is -1, which is a special case. This is in contrast to oxygen's usual oxidation state of -2 in most other compounds.

Answer 1

The Correct Option is A

Understanding Oxidation Numbers in Peroxides:
In most compounds, oxygen has an oxidation number of -2. However, in peroxides, oxygen atoms are bonded to each other in an O–O single bond, which affects their oxidation state.

Example of a peroxide:
Hydrogen peroxide (H₂O₂)

Step-by-step calculation in H₂O₂:
Let the oxidation number of each oxygen be x.
Hydrogen has an oxidation number of +1.
The overall charge of the molecule is 0.
So the equation becomes:
(2 × +1) + (2 × x) = 0 → 2 + 2x = 0 → x = -1

Final Answer: Option 1: -1