Question

Which one of the following has the highest octane number?

• A. Straight chain aliphatic compound
• B. Branched chain aliphatic compound
• C. Aromatic compound
• D. Cyclic aliphatic compound

Answer 1

Answer: (C)

Aromatic compound

An aromatic compound has the highest octane number. The octane number of aromatic hydrocarbons are exceptionally high.
Note: In case of straight chain hydrocarbons, octane number decreases with increase in the length of the chain.
Branching of chain increases the value of octane number.
Introduction of multiple bonds increases the value of the octane number.
Cyclic alkanes have the relatively higher value of octane number.