Technical soda, the mass fraction of impurities in which is 5%, was treated with hydrochloric acid

Technical soda, the mass fraction of impurities in which is 5%, was treated with hydrochloric acid. Emitted 4 mol of CO2. Calculate the mass of technical soda that has entered into a chemical reaction.

Given:
w approx. (Na2CO3) = 5%
n (CO2) = 4 mol
To find:
m mixture (Na2CO3)
Decision:
Na2CO3 + 2HCl = 2NaCl + H2O + CO2
w is clean. islands (Na2CO3) = 100% -5% = 95% = 0.95
n (CO2): n (Na2CO3) = 1: 1
n (Na2CO3) = 4 mol
m in islands (Na2CO3) = n * M = 4 mol * 106 g / mol = 424 g
m mixture (Na2CO3) = m water / w pure. in-va = 424 g / 0.95 = 446 g
Answer: 446 g