If `B-Cl` bond has a dipole moment, explain why `BCl_(3)` molecule has zero dipole moment.

Explanation

As a result of the difference in the electronegativities of B and Cl, the B–Cl bond is polar in nature. However, the `BCl_(3)` molecule is non-polar. This is because `BCl_(3)` is trigonal planar in shape. It is a symmetrical molecule. Hence, the respective dipole-moments of the B–Cl bond cancel each other, thereby causing a zero-dipole moment.