Question

Which statement is true about BF3, a nonpolar molecule? It has nonpolar bonds and a symmetrical structure. It has nonpolar bonds and an asymmetrical structure. It has polar bonds and a symmetrical structure. It has polar bonds and an asymmetrical structure. It has ionic bonds and symmetrical structure.

Answer 1

I think the correct answer is the first option. It has nonpolar bonds and a symmetrical structure. The structure of a BF3 molecule shows a symmetrical trigonal geometry. The net dipole moment of the molecule is zero therefore it is polar.

Answer 2

Answer: It has polar bonds and a symmetrical structure.

Explanation:

Formula used  for calculating hybridization

$:{\text{Number of electrons}} =\frac{1}{2}[V+N-C+A]$

where, V = number of valence electrons present in central atom i.e. boron= 3

N = number of monovalent atoms bonded to central atom=3

C = charge of cation = 0

A = charge of anion = 0

$BF_3$

${\text{Number of electrons}} =\frac{1}{2}[3+3-0+0]=3$

The number of electrons is 3 that means the hybridization will be $sp^2$ and the electronic geometry of the molecule will be trigonal planar.

Thus as there are no lone pair of electrons, there is no distortion and the molecule is symmetrical. The B-F bonds are polar due to electronegativity difference but the polarities cancel due to symmetrical structure.