Question

why saturated carbon give clean flame while unsaturated give black smoke? and plz tell any important topic of carbon chapter of class 10

Answer 1

saturated hydrocarbons have single bonds only like C6H14 CH4 etc while unsaturated hydrocarbons have double and triple bond
nomenclature of hydrocarbons you should be familiar with it it is imp topic

Answer 2

The reason being that the carbon content of unsaturated compounds is more than the hydrogen content and hence carbon is not completely burned and the unburned carbon deposits as a sooty and ultimately gives black smoke

But such condition doesn't appear in saturated hydrocarbon

Nomenclature, chemical properties of carbon compounds, soap and detergents. This topics are important and comes regularly in exams