\(n_{KHSO_3}=\dfrac{1.2}{120}=0.01\left(mol\right)\)
\(n_{K_2SO_3}=\dfrac{1.58}{158}=0.01\left(mol\right)\)
\(n_{KOH}=n_{KHSO_3}+2n_{K_2SO_3}=0.01+2\cdot0.01=0.03\left(mol\right)\)
\(C_{M_{KOH}}=\dfrac{0.03}{0.1}=0.3\left(M\right)\)
\(n_{SO_2}=n_{KHSO_3}+n_{K_2SO_3}=0.01+0.01=0.02\left(mol\right)\)
\(V_{SO_2}=0.02\cdot22.4=0.448\left(l\right)\)