Question

Which molecule has polar bonding and is nonpolar?

Answer 1

Answer: $BF_3$

Explanation:

A polar covalent bond is defined as the bond which is formed when there is a difference of electronegativities between the atoms. It is also defined as the bond which is formed due to the unequal sharing of electrons between the atoms.

If a molecule with polar covalent bonds is symmetrical in nature, it cancels out the dipole moments and thus the molecule becomes non polar. Example: $BF_3$

If a molecule with polar covalent bonds is asymmetrical in nature, dipole moments do not cancel and thus the molecule remains polar. Ex:$H_2O$, $NH_3$, $NCl_3$ and $CH_2Cl_2$

Answer 2

2.) BF3 is symmetrical. Resultant of dipole moment of two B-F cancels with the dipole of third B-F bond. Hence the net dipole moment is zero and molecule is non-polar.