JEE Chemistry 2023 Question with Solution

Given: Hydrocarbon $X$ has molecular formula $C_6H_8$ and consumes two moles of $H_2$ on catalytic hydrogenation of one mole of $X$.

Find: The structure of hydrocarbon $X$.

Catalytic hydrogenation using $2$ moles of $H_2$ shows that $X$ contains two double bonds.

On ozonolysis, $X$ gives two moles of methane dicarbaldehyde. This cleavage pattern matches a six-membered ring having double bonds at the $1,4$-positions, because each double bond cleavage produces aldehyde ends and the ring splits into two identical molecules of methane dicarbaldehyde.

Therefore, the hydrocarbon is cyclohexa-$1, 4$-diene. The correct option is D.

Given: $C_6H_8$ hydrocarbon, hydrogenation consumes $2$ moles of $H_2$, and ozonolysis gives $2$ moles of methane dicarbaldehyde.

Find: Which option matches the structure.

From hydrogenation, the compound must have two $C=C$ bonds.

The ozonolysis product is specifically methane dicarbaldehyde, so the parent diene must cleave in such a way that the ring opens into two identical three-carbon dialdehyde fragments.

This requirement is satisfied by cyclohexa-$1, 4$-diene. Hence the correct option is D.