What volume of hydrogen will be released when 20 g of zinc, containing 5% impurities with hydrochloric acid, react?

We carry out the solution:
1. By condition, write down the equation:
m = 20 g; 5% impurity; X l. -?
Zn + 2HCl = ZnCl2 + H2 – OBP, hydrogen is evolved;
2. Calculations:
M (Zn) = 65.3 g / mol;
M (H2) = 2 g / mol;
m (Zn) = 20 * (1 – 0.5) = 10 g (mass without impurity).
3. Determine the amount of the original substance:
Y (Zn) = m / M = 10 / 65.3 = 0.15 mol;
Y (H2) = 0.15 mol since the amount of substances according to the equation is 1 mol.
4. Find the volume of the product:
V (H2) = 0.15 * 22.4 = 3.36 l.
Answer: Hydrogen was obtained with a volume of 3.36 liters.