Question

Bromine test differentiates Benzene and Cyclohexane by:

• A. odour change
• B. effervescenes
• C. colour change
• D. evolution of hydrogen gas

Answer 1

Answer: (C)

colour change

Cyclohexane will undergo free-radical reaction with bromine in the presence of light which is indicated by the lost of orange color of bromine upon addition of cyclohexane and exposure to light for 10 minutes.

On the other hand, benzene will not react with bromine upon exposure to light since bromination reaction of benzene will require a catalyst. The orange color of the test solution will remain upon addition of benzene and exposure to light for 10 minutes.