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JEE Main levelSingle correct optionDifficulty 2 of 3o4097

Ethanol is heated with conc. $H X_{2} SO X_{4}$ at 413 K with excess alcohol, forming ethoxyethane. The carbon-oxygen bond of the ether is formed by

Aan E2 step on ethyl hydrogen sulfate
Battack of a molecule of ethanol on protonated ethanol (an SN2 step)
Cattack of ethoxide on a free ethyl carbocation
Dattack of ethanol on a free ethyl carbocation

Answer: B

Ethanol is protonated to

CH X_{3} CH X_{2} OH X_{2} X^{+}

. A primary cation is too unstable to form, so a second ethanol molecule displaces water by SN2, and loss of a proton gives

CH X_{3} CH X_{2} OCH X_{2} CH X_{3}

. At 443 K, elimination takes over.

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