Question

A cycloalkane having vapour density $35$ gives single monochlorinated product upon chlorination. The number of hydrogen present in the cycloalkane is:

Answer 1

Given: $\text{Vapour density}=35$
$\text{Molecular weight}=\text{Vapour density}\times 2$
$=35\times 2=70$
General formula for cycloalkane having one ring is $C_n{H}_{2n}$
$\therefore 12n+2n=70$
$\Rightarrow n=5$
Hence the formula for the cycloalkane is $C_5{H}_{10}$ and this is cyclopentane which gives single monochlosubstituted product upon chlorination.