Question

Which of the following molecules has a dipole moment that is not zero?

(1) CBr₄   (2) PCl₃ (3) SO₃  

Answer 1

(2) PCl₃

CBr4 is tetrahedral molecule and which is symmetric, mutual cancellation of polarity makes this molecule with no dipole moment.

SO3; central atom is S having 6 valance electrons. Which form 3 pi bonds with 3 oxygen atoms. So, So3 have sp2 hybridization (trigonal planar geometry)with mutual canellation of polarity makes this compound with no dipole moment.

PCl3 is Pyramidal and it show net dipole moment.