During the hydration of an alkyne using dilute , what is the specific role of (from ) as a catalyst? — Reaction Mechanism Chemistry Question

💡 Solution & Explanation

The addition of water to alkynes is catalyzed by $Hg^{2+}$. The $Hg^{2+}$ ion acts as a strong electrophile, forming a bridged mercurinium ion intermediate with the alkyne's $\pi$ -electrons. This significantly increases the electrophilicity of the alkyne carbons, making them susceptible to nucleophilic attack by the weak nucleophile, water, forming an enol which subsequently tautomerizes to a ketone.