Concept:The indirect hydration of alkenes involves intermediate formation of an alkyl hydrogen sulfate, which is then hydrolyzed by water to produce an alcohol.
Formula:$$ \text{CH}_2=\text{CH}_2 + \text{H}_2\text{SO}_4 \rightarrow \text{CH}_3\text{CH}_2\text{OSO}_3\text{H} $$
$$ \text{CH}_3\text{CH}_2\text{OSO}_3\text{H} + \text{H}_2\text{O} \xrightarrow{\text{boil}} \text{CH}_3\text{CH}_2\text{OH} + \text{H}_2\text{SO}_4 $$
Solution:- Ethene reacts with cold concentrated \( \text{H}_2\text{SO}_4 \) via electrophilic addition to form ethyl hydrogen sulfate.
- When this intermediate is boiled with water, a hydrolysis reaction occurs, stripping the sulfate group and replacing it with a hydroxyl group (\( -\text{OH} \)).
- The final product is the two-carbon alcohol, Ethanol.
Why other options are incorrect:- Ethyne is an alkyne, representing a higher oxidation state.
- Ethanal is an aldehyde, which would require an oxidation step.
- Ethane requires direct catalytic hydrogenation (addition of \( \text{H}_2 \)), not hydration.
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