Find the total number of non-polar compounds among the following.

$\begin{array}{r}{\mathrm{BCl}}_2\mathrm{F},{\mathrm{BF}}_3,{\mathrm{SF}}_6,{\mathrm{SOCl}}_2,{\mathrm{COCl}}_2,{\mathrm{B}}_3{\mathrm{N}}_3{\mathrm{H}}_6,{\mathrm{PCl}}_3{\mathrm{F}}_2,{\mathrm{PF}}_3{\mathrm{Cl}}_2\end{array}$

The non-polar compounds are ${\mathrm{BF}}_3,{ \mathrm{SF}}_6, {\mathrm{B}}_3{\mathrm{N}}_3{\mathrm{H}}_6,{ \mathrm{PCl}}_3{\mathrm{F}}_2$ 

There are no positive or negative poles created in a ${\mathrm{BF}}_3,{ \mathrm{SF}}_6, {\mathrm{B}}_3{\mathrm{N}}_3{\mathrm{H}}_6,{ \mathrm{PCl}}_3{\mathrm{F}}_2$ since there is no charge separation. In other words, nonpolar molecules' electrical charges are uniformly dispersed throughout the molecule.

Hence, the total number of non-polar compounds is 4.