Question

saturated hydrocarbon will generally give screen flame while unsaturated carbon compounds will give a yellow flame with lots of black smoke on burning .
why?

Answer 1

Saturated hydrocarbon gives clean and smoke less flame but Unsaturated hydrocarbon gives a yellow flame and lots of smoke on burning because due incomplete combustion.  With the proper supply of oxygen the Unsaturated hydrocarbon will also give a clean and smoke less flame