What would be more acidic? SO2 or SO3?

Does this have to do something with the higher oxidation state? And why is that?

Or can we say SO3 is more acidic by,
SO2+H2O--->H2SO3
SO3+H2O--->H2SO4

as H2SO4 is more acidic?

2 answers

Your second thought is right on. H2SO4 is a stronger acid than H2SO3. However, a clarification needs to be made. I don't think it's proper t ask if SO2 or SO3 is more acidic. I think what you means is "is an aqueous SOLUTION of SO2 or an aqueous SOLUTION of SO3 more acidic?"
Yes that is what I meant! :-)