39 grams of technical zinc, containing 20% impurities, was dissolved in an excess of hydrochloric acid.

39 grams of technical zinc, containing 20% impurities, was dissolved in an excess of hydrochloric acid. Find the volume of hydrogen produced and the amount of salt matter.

Given:
m (Zn tech.) = 39 g.
w% (approx.) = 20%
V (H2) -?
n (salt) -?

Decision:
1) Zn + 2HCl = ZnCl2 + H2
2) w% (Zn) = 100% -20% = 80%
3) m (Zn) = 39 * 80/100 = 31.2 g.
4) n (Zn) = 31.2 / 65 = 0.48 mol
5) at ur. n (Zn) = n (H2) = 0.48 mol
6) V (H2) = 0.48 * 22.4 = 10.752 L
7) n (salt) = 0.48 mol also according to ur.

Answer: 10.752 L, 0.48 mol.