SN1 and SN2 in Organic Substitution

Nucleophilic substitution reactions replace one group in a molecule with another. In these reactions, a nucleophile, which is a Lewis base, reacts with an electrophile, which is a Lewis acid. The nucleophile takes the place of a halogen atom bonded to carbon and releases a stable ion called the leaving group.

Many organic chemistry reactions proceed under acid or base-catalyzed conditions, including nucleophilic substitution reactions.

Consider a simple acid-base reaction of hydrochloric acid with sodium hydroxide. Here, the hydroxide ion is an electron-rich species and acts as a Lewis base. It deprotonates the acidic hydrogen, forming water a...