What volume of hydrogen sulfide should be dissolved in water m = 300 g

What volume of hydrogen sulfide should be dissolved in water m = 300 g to obtain a solution of hydrogen sulfide acid with a mass fraction of H2S = 1.2%.

Given:
m (H2O) = 300 g
ω (H2S) = 1.2%

To find:
V (H2S) -?

1) Let m (H2S) = (x) r;
2) m solution (H2S) = m (H2S) + m (H2O) = (x + 300) g;
3) m solution (H2S) = m * 100% / ω = (x * 100% / 1.2%) = (100x / 1.2) g;
4) x + 300 = (100x / 1.2);
x = 3.64;
5) n (H2S) = m / M = 3.64 / 34 = 0.11 mol;
6) V (H2S) = n * Vm = 0.11 * 22.4 = 2.5 liters.

Answer: The volume of H2S is 2.5 liters.