JEE Main 2014 — Haloalkanes and Haloarenes Question with Solution

C-halogen bond length totally depends on the electronegativity difference between Carbon and halogen. The more the difference and the less is the bond length. The electronegativity order of halogens is $\mathrm{I}<\mathrm{Br}<\mathrm{Cl}<\mathrm{F}$. Hence, the correct order of increasing C-halogen bond length is $\mathrm{CH}3\mathrm{F}<\mathrm{CH}3\mathrm{Cl}<\mathrm{CH}3\mathrm{Br}<\mathrm{CH}3\mathrm{I}.$

Or we can say that as the size of halogen increases C-halogen bond length also increases.