Question

substitution reactions and addition reaction are the charecteristic properties of saturated and unsaturated hydrocarbons respectively distinguish betwn substitution and adition reaction by taking an example of methane and ethane respectively

Answer 1

A type of reaction in which one type of atom or a group of atoms takesvthe place of another is called substitution reaction.
CH4 +Cl2 → CH3Cl + HCl (in presence of sunlight)

The addition of hydrogen by unsaturated hydrocarbons in the presence of catalysts such as nickel or palladium to give saturated hydrocarbons is called addition reaction.
Ethene in presence of nickel catalyst gives ethane.
C2H4 → C2H6


Hope it helps...

Answer 2

Addition reaction is a type of reaction in which two or more molecules combine with each other to form a single substance. ... Substitution reaction does not add any atom to the hydrocarbon because it takes place only in saturated hydrocarbons(containing only single bonds).