What is the VSEPR shape of #SO_2#?

1 Answer
Mar 21, 2016

Answer:

The molecule is bent around the central sulfur, with an #/_O-S-O# #=# #<120""^@#.

Explanation:

There are 18 valence electrons to distribute around the molecule; and the least electronegative atom, sulfur, is ASSUMED to be central.

Resonance structures of #""^(-)O-S^(+)=O# and #""^(-)O-S^(2+)-O^-# are valid. In either case there are 3 regions of electron density around the central sulfur: a lone pair, and #2xxS-O# bonds, The electronic geometry should be based on a trigonal plane. But, because we describe molecular geometry on the basis of bonds not electron pairs, we describe the geometry of #SO_2# as bent. The actual molecule has #/_O-S-O# #=# #119""^@#.