Question

Alkane generally give clear flame why?

Answer 1

Alkane give clear flame because a very small amount of energy is required for transfer of its electron to excited state , hence absorbing very less energy and emitting most of the energy in form of lights of all wavelength

Answer 2

Alkane is a saturated hydrocarbon.

saturated hydrocarbon generally give a clean flame.

this is the reason why Alkane give a clear flame