JEE Chemistry 2025 Question with Solution

Given: The compound shown is a substituted benzoic acid.

Find: The correct IUPAC name.

The main functional group is carboxylic acid, so the parent compound is benzoic acid. The carbon attached to $\text{CO}_2\text{H}$ is assigned position $1$.

From the structure, the substituents are:

• $\text{OH}$ at position $2$
• $\text{Br}$ at position $3$
• $\text{NO}_2$ at position $5$

In IUPAC nomenclature, the substituent prefixes are written in alphabetical order: bromo, hydroxy, nitro.

Therefore, the correct IUPAC name is $3$-Bromo-$2$-hydroxy-$5$-nitrobenzoic acid. Hence, the correct option is A.

Given: A benzene ring bearing $\text{CO}_2\text{H}$, $\text{OH}$, $\text{Br}$ and $\text{NO}_2$ substituents.

Find: The correct IUPAC name after proper numbering and ordering.

The parent is benzoic acid because the ring contains a carboxylic acid group. Thus, $\text{CO}_2\text{H}$ must be at position $1$.

Now choose the direction of numbering that gives the lowest locants to the remaining substituents. Clockwise numbering gives:

• $\text{OH}$ at $2$
• $\text{Br}$ at $3$
• $\text{NO}_2$ at $5$

The opposite direction would place $\text{OH}$ at $6$, which is not preferred.

After numbering, list substituents alphabetically by name, not by position. So the order is bromo, hydroxy, nitro.

Hence the name is $3$-bromo-$2$-hydroxy-$5$-nitrobenzoic acid. This matches option A.