PTHH: \(SO_2+Ca\left(OH\right)_2\rightarrow CaSO_3+H_2O\)
Ta có: \(n_{SO_2}=\dfrac{0,056}{22,4}=0,0025\left(mol\right)=n_{Ca\left(OH\right)_2}=n_{CaSO_3}\)
\(\Rightarrow\left\{{}\begin{matrix}C_{M_{Ca\left(OH\right)_2}}=\dfrac{0,0025}{0,35}\approx0,007\left(M\right)\\m_{CaSO_3}=0,0025\cdot120=0,3\left(g\right)\end{matrix}\right.\)