Question

In the case of $C{H}_{3}COOH$, the oxidation number of carbon of the carboxylic group is:

• A. $-3$
• B. zero
• C. $+1$
• D. $+3$

Answer 1

The correct option is D $+3$

Acetic acid is represented as $C{H}_3-\underset{\underset{O}{||}}{C}-OH$. For the purpose of oxidation number calculation, the oxidation number of C atom of methyl group is considered 0, the oxidation number of oxygen atom of $C=O$ double bond is considered $-2$. The oxidation number of oxygen atom of hydroxyl group is considered $-1$.

Let $x$ be the oxidation number of C atom of carboxylic group.

$x+0+(-2)+(-1)=0$
$x-3=0$
$x=+3$

Hence, in the case of $C{H}_{3}COOH$, the oxidation number of carbon of the carboxylic group is $+3$.