PTHH: \(SO_2+2NaOH\rightarrow Na_2SO_3+H_2O\)
Ta có: \(n_{NaOH}=0,4\cdot2=0,8\left(mol\right)\)
\(\Rightarrow n_{SO_2}=0,4\left(mol\right)=n_{Na_2SO_3}\) \(\Rightarrow\left\{{}\begin{matrix}V_{SO_2}=0,4\cdot22,4=8,96\left(l\right)\\m_{Na_2SO_3}=0,4\cdot126=50,4\left(g\right)\\C_{M_{Na_2SO_3}}=\dfrac{0,4}{0,4}=1\left(M\right)\end{matrix}\right.\)