Question

A hydrocarbon C5​H10​ does not react with chlorine in dark but gives a single monochloro compound C5​H9​Cl in bright sunlight. Identify the hydrocarbon.​

Answer 1

The molecular formula of hydrocarbon is C5H10. It satisfies the general formula CnH2n . It suggests that the hydrocarbon is either alkene or cyclloalkane. It does not react with chlorine in dark. Hence, it cannot be alkene. Hence, it is cycloalkane. It gives a single monochloro compound C5H9Cl in bright sunlight. Hence, the hydrocarbon.is cyclopentane.

Answer 2

Answer

A hydrocarbon with the molecular formula, C5H10 belongs to the group with a general molecular formula CnH2n. Therefore, it may either be an alkene or a cycloalkane.

Since hydrocarbon does not react with chlorine in the dark, it cannot be an alkene. Thus, it should be a cycloalkane.

Further, the hydrocarbon gives a single monochloro compound, C5H9Cl by reacting with chlorine in bright sunlight. Since a single monochloro compound is formed, the hydrocarbon must contain H-atoms that are all equivalent. Also, as all H-atoms of a cycloalkane are equivalent, the hydrocarbon must be a cycloalkane. Hence, the said compound is cyclopentane.