JEE Chemistry 2026 Question with Solution

Given: Two statements about compounds $(X)$ and $(Y)$ are to be checked.

Find: Which statement is true and which is false.

For Statement I, solubility in $NaHCO_3$ indicates the presence of an acidic group such as $-COOH$. The given compound contains a carboxylic acid group, so it reacts with sodium bicarbonate and dissolves.

The structure also has two chiral carbon atoms. As stated in the solution, the fragment $-C^*H(OH)C^*H(CH_3)COOH$ has two starred carbons, and each is attached to four different groups. Therefore, Statement I is true.

For Statement II, analyze the hybridization in $CH_3-CH_2-C \equiv C-C(=O)H$.

• The $CH_3$ and $CH_2$ carbons are $sp^3$ hybridized. Count $= 2$.
• The carbonyl carbon $C=O$ is $sp^2$ hybridized. Count $= 1$.
• The two carbons in the triple bond $C \equiv C$ are both $sp$ hybridized. Count $= 2$.

So the statement claiming only one carbon is $sp$ hybridized is incorrect. Therefore, Statement II is false.

Hence, Statement I is true but Statement II is false. The correct option is D.

Given:

• Solubility in $NaHCO_3$ is mentioned for compound $(X)$.
• Hybridization counts are mentioned for compound $(Y)$.

Find: Evaluate both statements.

Concept 1: Compounds that dissolve in $NaHCO_3$ generally contain a sufficiently acidic proton, especially the carboxylic acid group $-COOH$, which reacts to release $CO_2$.

Concept 2: A chiral carbon must be bonded to four different substituents.

Concept 3:

• Tetrahedral carbon $\rightarrow sp^3$
• Trigonal planar carbon $\rightarrow sp^2$
• Linear carbon in triple bond $\rightarrow sp$

Applying these:

1. Compound $(X)$ contains a carboxylic acid group, so dissolution in $NaHCO_3$ is justified.
2. The indicated two starred carbons each have four different groups attached, so there are two chiral centers.
3. Thus, Statement I is true.
4. In compound $(Y)$, the two saturated carbons $CH_3$ and $CH_2$ are $sp^3$.
5. The aldehyde carbonyl carbon is $sp^2$.
6. The alkyne unit contains two $sp$ carbons, not one.
7. Thus, Statement II is false.

Therefore, the correct option is D.