Question

Why saturated hydrocarbons give a blue flame or clean flame whereas unsaturated hydrocarbons give yellow flame?????

Answer 1

saturated hydrocarbon give a because in saturated hydrocarbon Oxygen supply is sufficient then the fuel burn completely produce blue flame or clean flame +/ unsaturated hydrocarbon is for weight by weight,they contain more carbon than a saturated hydrocarbon and will require more air for complete combustion .lf you use them in a burner burning saturated hydrocarbon,it will give a yellow flame if you don't change the air flow yellow flame is an indication of incomplete burning

Answer 2

that have double or triple covalent bondsbetween adjacent carbon atoms. Those with at least one carbon-to-carbon double bond are called alkenes and those with at least one carbon-to-carbon triple bond are called alkynes. The position of the double or triple bond is shown by a number written either at the start of the name, or just before the -ene or -yne suffix (e.g. pent-2-ene and 2-butyne). The number represents the position of the first of the two carbons making the bond, in the longest carbon chain. Alkenes and alkynes with more than one double or triple bond respectively are named with a prefix preceding the -ene or -yne (e.g. 2,4-pentadiene).

Unsaturated hydrocarbons with both double and triple bonds have the suffix -enyne and are handled in a similar manner.

The physical properties of unsaturated hydrocarbons are very similar to those of the corresponding saturated compounds. They are typically only sparingly soluble in water.

Except for aromatic compounds, unsaturated hydrocarbons are reactive and undergo addition reactions to their multiple bonds. Typical reagents added are hydrogen halides, water, sulfuric acid, elemental halogens, and alcohols.