An excess of dilute sulfuric acid was added to 150 g of sodium carbonate solution and the solution was heated until gas evolution ceased

An excess of dilute sulfuric acid was added to 150 g of sodium carbonate solution and the solution was heated until gas evolution ceased. A total of 4.48 liters of gas were released. Calculate the mass fraction of sodium carbonate in the original solution.

1) Let’s compose the reaction equation:
Na2CO3 + H2SO4 = Na2SO4 + CO2 ↑ + H2O
2) Calculate the amount of substance and the mass of sodium carbonate:
n (CO2) = V (CO2) / Vm = 4.48 / 22.4 = 0.2 mol.
according to the reaction equation
n (Na2CO3) = n (CO2) = 0.2 mol
m (Na2CO3) = n (Na2CO3) ∙ M (Na2CO3) = 0.2 ∙ 106 = 21.2 g.
3) Determine the mass fraction of sodium carbonate in the solution:
ω (Na2CO3) = (m (Na2CO3) / m (solution)) ∙ 100% = (21.2 / 150) ∙ 100 = 14.13%
Answer: 14.13%.