How much chlorine is needed if 100 g of 15% hydrochloric acid is obtained by dissolving

How much chlorine is needed if 100 g of 15% hydrochloric acid is obtained by dissolving hydrogen chloride in water?

Given:
m solution (HCl) = 100 g
ω (HCl) = 15%

To find:
V (Cl2) -?

1) Cl2 + H2 => 2HCl;
2) m (HCl) = ω * m solution / 100% = 15% * 100/100% = 15 g;
3) n (HCl) = m / M = 15 / 36.5 = 0.41 mol;
4) n (Cl2) = n (HCl) / 2 = 0.41 / 2 = 0.21 mol;
5) V (Cl2) = n * Vm = 0.21 * 22.4 = 4.7 liters.

Answer: The volume of Cl2 is 4.7 liters.