Question

Assertion : $2-$ bromobutane on reaction with sodium ethoxide in ethanol gives $1-$ butene as a major product.
Reason : $1-$ butene is more stable than $2-$ butene.

• A. If both assertion and reason are true and reason is the correct explanation of assertion
• B. If both assertion and reason are true but reason is not the correct explanation of assertion
• C. If assertion is true but reason is false
• D. If both assertion and reason are false

Answer 1

Answer: (D)

$2$-bromobutane undergo dehydrohalogenation in presence of strong alkali like sodium ethoxide in ethanol. The elimination is according to Saytzeff rule-"During dehydrohalogenation $H$ is eliminated so as to form more alkylated alkene i.e., from the carbon atom which has less $H$ atoms.

$2$-butene is more stable than $1$-butene due to presence of large number of hyperconjugating structures of $2$-butene.