Question

What is formed on aromatisation of heptane?

• A. Benzene
• B. Toluene
• C. Xylene
• D. Ethylbenzene

Hint:

Remember the important aromatisation reactions: \[ \boxed{ \begin{aligned} C_6H_{14} &\rightarrow C_6H_6 \quad (\text{Benzene})\\ C_7H_{16} &\rightarrow C_6H_5CH_3 \quad (\text{Toluene})\\ C_8H_{18} &\rightarrow C_6H_4(CH_3)_2 \quad (\text{Xylene}) \end{aligned} } \] These conversions are frequently asked in examinations.

Answer 1

The Correct Option is B

Heptane ($C_7H_{16}$) undergoes dehydrocyclization (aromatization) over a Pt or Re catalyst at high temperature to form toluene ($C_7H_8$), releasing four molecules of $H_2$. The process involves cyclization of the seven-carbon chain into a six-membered ring followed by successive dehydrogenation to restore aromaticity.