Question

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

• 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 $H_{2}C=C{H}^{-}$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 $H_{2}C=C{H}^{-}$.