Are SO3,XeF2,IF2^- polar or nonpolar?How it is polar or nonpolar?


  1. Are SO3,XeF2,IF2^- polar or nonpolar?How it is polar or nonpolar?Add formal charges and bond dipoles to lewis dot structuresof SO3,XeF2,IF2^-.Fully explain your answer.

  2. according to Vallence bond theory , what is the hybridization of all atoms in SO3?Describe the orbitals that overlap to form all bonds in SO3.



Yes they are all polar because they have formal charges non-zero

b) It doesn’t really have 3 double bonds, more like 3 - 1 1/3 bonds.

There are two ways to explain the bonding in SO3. What is commonly told to students is that sulfur can expand its octet by using the empty 3d orbitals. This gives sulfur more “room” to accommodate extra electrons, extending its valency beyond 2. Elements in period 3 and beyond can do this. This is a “valence bond theory” explanation. This configuration also reduces “formal charge”, which is a fictitious assignment of charge to describe electron density around an atom. In Lewis structures you want to minimize this.

The explanation that is closer to the truth is the molecular orbital theory explanation. This says that the 3p orbital of sulfur and the 2p orbitals of oxygen that lie perpendicular to the plane of the molecule are participating in resonance or pi delocalization. This essentially means that all 4 of these orbitals are overlapping to some degree and equally sharing the electron density between the 3 S-O bonds. This is why I said that SO3 has 3- 1 1/3 bonds because in this model, each S-O bond gets 1/3 of the pi bond density.