Question

Which of the following is a polar molecule?

• A. $Xe{F}_4$
• B. $B{F}_3$
• C. $C_2{F}_4$
• D. $P{F}_{3}C{l}_2$

Answer 1

The correct option is D $P{F}_{3}C{l}_2$

The hybridisation of $Xe{F}_4$ is $s{p}^3{d}^2$ and its shape is square planner. thus the net dipole moment for the molecule is zero.
In $B{F}_3$ also hybridisation is $s{p}^2$ and the shape is trigonal planner. Thus it has also zero net dipole moment and hence it is non polar.

Similarly $C2F_4$ also has planner symmetrical shape and hence it is also non polar.


In $PC{l}_2{F}_3$, net dipole moment does not cancel out since the shape is not symmetrical. It is trigonal biypyramidal shape . Two of the F atoms occupy the axial position and one F atom occupies the equitorial position since it is the most electronegative atom.