Which would undergo `S_(N)1` reaction faster in the following pair :
`CH_(3)-CH_(2)-CH_(2)-Br and CH_(3)-underset(Br)underset(|)CH-CH_(3)`

Explanation

A tertiary alkyl tends to undergo the `S_(N)1` mechanism because it can form a tertiary carbocation, which is stablized by the three alkyl groups attached to it. As alkyl group are electron donating, they allow the positive charge in the carbocation to be delocalised by the induction effect. Hence out of the given pair `(CH_(3))_(3)` CBr would undergo `S_(N)1` reaction faster than `CH_(3)-CH_(2)-Br`