A hydrocarbon `C_(5)H_(10)` does not react with chlorine in dark but gives a single monochloro compound `C_(5)H_(9)Cl` in bright sunlight. Identify the hydrocarbon.

Explanation

(i) The hydrocarbon with M.F. `C_(5)H_(10)` can be either a cycloalkane or an alkene.
(ii) Since the hydrocarbon does not react with `Cl_(2)` in th dark, it cannot be an alkene but must be a cycloalkane.
(iii) Since the cycloalkane reacts with `Cl_(2)` in the presence of bright sunlight, to give a single monochloro compound, `C_(5)H_(9)Cl`, therefore, all the ten hydrogen atoms of the cycloalkane must be equivalent. thus,