Calculate the no. of gramSO2 formed by treatment of 100g Na2SO3 with HCl.

The solution is as follows:

The reaction is:

Na₂SO₃(aq) + 2 HCl(aq) $\to$2 NaCl(aq) + H₂O(l) + SO₂(g)

1 mole of Na₂SO₃ produces 1 mole of SO₂ gas,

Thus, Number of moles in 100 g of Na₂SO₃ = $$\begin{gathered} \frac{100}{126.043}=0.79 moles \\ Mass of 0.79 moles of S{O}_2 = 0.79\times 64 = 50.77 g \end{gathered}$$