When 12 g of magnesium, containing 2.5 percent of impurities, interacted with an excess of hydrochloric

When 12 g of magnesium, containing 2.5 percent of impurities, interacted with an excess of hydrochloric acid, gas was released. Calculate the amount of gas evolved.

Mg + 2HCl = MgCl2 + H2 – OBP, hydrogen is evolved;
Calculations by formulas:
M (Mg) = 24.3 g / mol;

M (H2) = 2 g / mol;

m (Mg) = 12 (1 – 0.025) = 11.7 g (mass without impurity).

Determine the amount of the original substance:
Y (Mg) = m / M = 11.7 / 24.3 = 0.48 mol;

Y (H2) = 0.48 mol since the amount of substances is 1 mol.

We find the volume of H2:
V (H2) = 0.48 * 22.4 = 10.75 L

Answer: Hydrogen was obtained with a volume of 10.75 liters.