Question

Explain the mechanism of alkaline hydrolysis of bromomethane.

Answer 1

Alkaline hydrolysis involves the reaction of bromomethane (CH₃Br) with aqueous sodium hydroxide (NaOH) to form methanol (CH₃OH) and sodium bromide (NaBr).

\[\ce{CH3​Br + NaOH -> CH3​OH + NaBr}\]

Mechanism:

• The hydroxide ion (OH⁻), a strong nucleophile, attacks the electrophilic carbon of bromomethane.
• Bromomethane undergoes an SN₂ nucleophilic substitution where the OH⁻ attacks from the back side, displacing the bromide ion (Br⁻).

Step-by-step:

1. Nucleophile OH⁻ attacks the carbon bonded to Br.
2. C – Br bond breaks simultaneously and Br⁻ leaves.
3. Methanol (CH₃OH) is formed.

This is a bimolecular nucleophilic substitution (SN₂) mechanism.