Question

What is the oxidation number of As in H\(_3\)AsO\(_3\)?

• A. +4
• B. +2
• C. +3
• D. -3

Hint:

To calculate oxidation states, balance the charges in a molecule or ion considering the known oxidation states of other elements.

Answer 1

The Correct Option is C

Step 1: Understanding the oxidation number of As.
In H\(_3\)AsO\(_3\), hydrogen has an oxidation number of +1 and oxygen has an oxidation number of -2. To determine the oxidation number of As, we use the following equation: \[ \text{Oxidation number of As} + 3(+1) + 3(-2) = 0 \] \[ \text{Oxidation number of As} + 3 - 6 = 0 \] \[ \text{Oxidation number of As} = +3 \]
Step 2: Conclusion.
The oxidation number of As in H\(_3\)AsO\(_3\) is +3.