A sample of technical iron, the mass of which is 120 g, contains 30% of impurities.

A sample of technical iron, the mass of which is 120 g, contains 30% of impurities. Calculate the volume of gas that is formed when this sample interacts with HCl?

1) Let’s calculate the mass of pure iron, without impurities.

% pure iron = 100 – 30 = 70%

mch Fe = 120 * 0.7 = 84 g

2) Let’s calculate the number of moles of iron.

n (Fe) = m / M = 84 / 55.85 = 1.5 mol

3) According to the condition of the problem, it is necessary to find the volume of gas released during the interaction of iron with hydrochloric acid. The gas is hydrogen.

Fe + 2HCl = FeCl2 + H2

n (H2) = n (Fe) = 1.5 mol

V (H2) = n (H2) * Vm

Vm = 22.4 l (under standard conditions: 0 ° C, pressure 1 atm).

V (H2) = 1.5 * 22.4 = 33.6 L