Question

Assertion : $HC \equiv C ^{-}$is more stable than $H _{2} C = CH ^{-}$.
Reason : $HC \equiv C ^{-}$has more s-character than $H _{2} C = CH ^{-}$.

• 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: (A)

$HC \equiv C ^{-}$has $50 \%$ s-character and $H _{2} C = CH ^{-}$has $33 \%$ s-character. Stability of carbanions increases with an increase in the s-character at the carbanion. So $HC \equiv C ^{-}$is more stable than $H _{2} C = CH ^{-}$.