Which is more electronegative SO3 or SO2, and why?
SO2 is non-polar in nature due to zero dipole moment and linear structure i.e charge is equally distributed among two oxygen of dioxide. Thus electronegativity is not high. But in case of trioxide the dipole moment is not zero due to trigonal geometry which allow the oxygen atom of trioxide to have electron more towards it. This makes SO3 a charged, polar and highly electronegative compound than SO2