Explain why (i) vinyl chloride is unreactive to nucleophilic substitution reactions. (ii) neo-Pentyl bromide undergoes nucleophilic substitution reaction very slowly.(iii) 3 - Bromocyclohexene is more reactive than 4-bromo cyclohexene in hydrolysis with aqueous NaOH.

Explain why (i) vinyl chloride is unreactive to nucleophilic substitut

1.	Explain why (i) vinyl chloride is unreactive to nucleophilic substitution reactions. (ii) neo-Pentyl bromide undergoes nucleophilic substitution reaction very slowly.(iii) 3 - Bromocyclohexene is more reactive than 4-bromo cyclohexene in hydrolysis with aqueous NaOH.
Answer» Solution :(i) Vinyl CHLORIDE is UNREACTIVE to nucleophilic substitution reactions because of the double bond character in C=C1 bond which is difficult to break. (ii) neo-Pentyl bromide undergoes nucleophilic substitution reaction very slowly. This is because it is a primary alkyl halide and it forms a primary carbocation which is less stable and therefore reacts slowly `("in"S_(N)1 )`. Even in `S_(N)2` reaction, the nucleophile FACES steric hindrance. Therefore the reaction is slow. (iii) 3 Bromocyclohexene 4-Bromocyclohexene Br 3-Bromocyclohexene forms a stable carbocation which reacts with `OH^(-)`ion to FORM the product. 4-Bromocyclohexene does not form the carbocation and therefore the reaction is slow.