Sodium carbonate reacts with dil. H2SO4 to give the respective salt, water and carbon dioxide. Calculate the mass of pure salt formed when 300 g. of Na2CO3 of 80% purity reacts with dil. H2SO4.
[Na = 23, C = 12, O = 16, H = 1, S = 32]

300 g. of Na₂CO₃ is of 80% purity

∴ Mass of pure Na₂CO₃ present in it = 80\over 100 × 300

= 240 g

We have,

Na₂CO₃ + H₂SO₄ → Na₂SO₄ + H₂O + CO₂

106 g                          142 g

106 g of Na₂CO₃ gives 142 g of Na₂SO₄

∴ 240 g of Na₂CO₃ gives = 142\over 106 × 240

= 321.51 g

Hence, mass of pure salt formed is 321.51 g