Question

What is the oxidation number of As in H₃AsO₃?

Options

• +4

• +3

• −3

• +2

Answer 1

+3

Explanation:

Oxidation number of As = +3.

H₃AsO₃

Let oxidation state of As = x

We know that, oxidation number of H = +1, O = −2

Putting the values in formula,

(1)3 + x + (−2)3 = 0

3 + x − 6 = 0

x = +3