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

In the given chemical compound $C{H_3}COOH$, two carbon atoms are present, one is of methyl group and one is of carboxylic acid group. The carbon of carboxylic acid is attached with one oxygen by double bond and one hydroxyl group by single bond. The oxidation number is the total number of electrons lost or gained during the bond formation.

Complete step by step answer:
The given chemical compound is $C{H_3}COOH$. The chemical name of the given chemical compound is ethanoic acid. Ethanoic acid is commonly known as acetic acid.
In this chemical compound, two carbon atoms are present, four hydrogen atoms are present, and two oxygen atoms are present. In $C{H_3}COOH$, $C{H_3}$ is a methyl group and COOH is the carboxylic acid group. The carbon of the methyl group is attached to three hydrogen atoms and with the carbon of carboxylic group. The carbon of the carboxylic group is attached to the oxygen atom with double bond and one hydroxyl group with a single bond.
The oxidation number is also referred to as the oxidation state which is defined as the total number of electrons which an atom either gains or loses to form a chemical bond with the neighbouring atom.
The oxidation number of carbon of methyl group is 0, the oxidation number of oxygen of C=O of carboxylic group is -2, the oxidation number of oxygen of hydroxyl group is -1.
The oxidation number of the carbon of the carboxylic group is calculated as shown below.
$\Rightarrow x + 0 + ( - 2) + ( - 1) = 0$
$\Rightarrow x - 3 = 0$
$\Rightarrow x = + 3$
Thus, the oxidation number of carbon of the carboxylic group is +3.
Therefore, the correct option is D.

Note:
Make sure to take the overall charge of the group as zero as the given compound is not an ion. We need to find the oxidation number of carbon present in the carboxylic group so the charge of the atoms present in the methyl group are neglected.