Assertion : trans-Pent-2-ene is polar but trans- but-2-ene is non-polar. Reason : The polarity of cis-isomer is more than trans-isomer, which are either non-polar or less polar.

• A

  If both assertion and reason are true and reason is the correct explanation of assertion.
• Correct answer
  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.

Solution

The vector sum of all polar bonds in trans-pent-2-ene is not zero while in trans-but-2-ene it is zero.

Hence, the correct answer is option: 'B'.