Write the mechanism of hydration of ethene to yield ethanol.

(N/A) The mechanism of acid-catalyzed hydration of ethene to form ethanol involves three steps:
Step $1$: Protonation of ethene to form a carbocation by electrophilic attack of $H_{3}O^{+}$:
$CH_{2}=CH_{2} + H_{3}O^{+} \rightleftharpoons CH_{3}-CH_{2}^{+} + H_{2}O$
Step $2$: Nucleophilic attack of water on the carbocation:
$CH_{3}-CH_{2}^{+} + H_{2}O \rightleftharpoons CH_{3}-CH_{2}-O^{+}H_{2}$
Step $3$: Deprotonation to form ethanol:
$CH_{3}-CH_{2}-O^{+}H_{2} + H_{2}O \rightleftharpoons CH_{3}-CH_{2}-OH + H_{3}O^{+}$