Question

Give reasons for the following:
(I) Ethane does not undergo addition reactions, but ethene does.
(II) Ethyne is more active than ethane.
(III) Hydrocarbon are excellent fuels.

Answer 1

1) addition reaction are the characteristic property of unsaturated hydrocarbon.ethene is an unsaturated hydrocarbon ,it undergoes addition reaction to become saturated hydrocarbon whereas ethane is saturated hydrocarbon therefore it does not undergo addition reaction.
2) ethyne is an unsaturated hydrocarbon and ethane is saturated hydrocarbon. ethyne are more active ethane due to the presence of C
triple bond which are generally weaker than C single bond.these reactive site in ethyne which can give easily addition reaction.
3) Hydrocarbons are organic molecules consisting entirely of carbon and hydrogen. ... They make good fuels because their covalent bonds store a large amount of energy, which is released when the molecules are burned (i.e., when they react with oxygen to form carbon dioxide and water).