Question

Assertion: 1-Butene has less dipole moment than 1-butyne.
Reason : 1-Butyne has more s-character.

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

Answer 1

The correct option is B If both assertion and reason are true and reason is correct explanation assertion.

1-Butyne has $sp$ hybridisation and more electronegative than double bonded carbon $\left(s{p}^2\right)$ in 1-butene, therefore, 1-butyne has more dipole moment than 1-butene.
1-Butyne (50% s- character) has more $s$-character than 1-butene (33% s-character).

Hence, option (a) is correct.