2NaOH+SO2=Na2SO3+H2O
2a a a
NaOH+SO2=NaHSO3
b b b
n(SO2)=a+b=67.2/22.4=3
m=126a+104b=356
得a=2,b=1
n(NaOH)=2a+b=5molNaHSO3加热不分解？NaHSO3加热不分解？