What is the steric number associated with the central atom, sulfur, in this molecule and what is the O–S–O bond angle predicted by VSEPR?

Question

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Options: 

 

SN = 2, 180°
SN = 3, 120°
SN = 3, 180°
SN = 2, 120°

Answer 1

SN = 3, 120°.

 

you have two oxygens and a lone pair = three groups so the angle will be around 120° (slightly less).

http://en.wikipedia.org/wiki/Sulfur_dioxide