Question

justify why trans pent 2 ene is polar and trans but 2 ene is not polar

Answer 1

dipole moment of trans compound to be zero

Answer 2

Explanation :

Trans pent-2-ene is polar molecule because it is an asymmetric molecule. In this molecule, the dipole moment are not equal in magnitude and direction. So, it will not be cancel by each other. Hence, there will be some net dipole moment.

Trans but-2-ene is non-polar molecule because it is a symmetric molecule. In this molecule, the dipole moment are equal in magnitude and direction. So, it will be cancel by each other. Hence, the  net dipole moment is equal to zero.

The structure of given molecules are shown below.