Question

Due to incomplete combustion, unsaturated hydrocarbon gives :

• A. yellow flames with black smoke.
• B. blue flame with black smoke.
• C. yellow flame with no smoke.
• D. no change in the colour of flame.

Answer 1

The correct option is A yellow flames with black smoke.

Saturated hydrocarbons give a clean flame due to their complete combustion whereas, unsaturated hydrocarbons give a yellow flame with lots of black smoke as they do not undergo complete combustion. The colour of the flame is yellow because of the presence of unburnt carbon particles.

Hence option A is correct.