The Nucleophilic substitution mechanism: i. give the mechanism for the reaction between bromoethane and sodium hydroxide solution; ii. explain why the reaction mechanism is called nucleophilic substitution mechanism.

ii. The nucleophile donates a lone pair of electrons to the electrophilic carbon atom in the halogenoalkene. The bromine atom is substituted by the hydroxide ion. The mechanism is accompanied by inversion of configuration (like an umbrella in a strong wind). Therefore, if a the starting material was chiral, the product would have its symmetry inverted.