(i)State one use each of DDT and iodoform.
(ii) Which compound in the folloeing couples will react faster in `S_(N)2 displacement and why?
(a)1-Bromopentane or2-bromopentane
(b) 1-Bromo -2 methylbutane or 2-bromo-2-methylbutane.

Explanation

(i) DDT is used as an insecticide and iodoform is used as a mild antiseptic.
(ii) (a) 1-Bromopentane, as it is a primary alkyl halide.
(b) 1-Bromo-2-methylbutane, as it is a primary alkyl halide.