Question

write the name and general formula of a chain of hydrocarbons in which an addition reaction with hydrogen is possible.state the essential condition for an addition reaction.stating this condition,write a chemical equation giving the name of the reactant and product of the reaction

Answer 1

Saturated hydrocarbons. (alkanes) general formula - C(n) H2(n)+2 where n = no. of carbon atoms. The essential condition is that the compound should be unsaturated. i.e. it should contain a double or triple bond. Catalysts are also needed for the reaction to take place. 
C2H4 + H2 --(nickel/palladium catalyst)---> C2H6