Calculate the mass of a 10% hydrochloric acid solution, which reacted with zinc to produce 6.72 liters of hydrogen.

Zinc metal reacts with hydrochloric (hydrochloric) acid to release hydrogen gas and form zinc chloride. The reaction is described by the following equation:

Zn + 2HCl = ZnCl2 + H2;

1 mole of metal reacts with 2 moles of acid. This synthesizes 1 mol of salt and 1 mol of hydrogen.

Let’s calculate the synthesized amount of hydrogen. To do this, we divide its volume by the volume of 1 mole of ideal gas, which is 22.4 liters.

N H2 = 6.72 / 22.4 = 0.3 mol;

To obtain such an amount of hydrogen, you need 0.3 x 2 = 0.6 mol of acid. Let’s calculate its weight.

M HCl = 1 + 35.5 = 36.5 grams / mol;

m HCl = 0.6 x 36.5 = 21.9 grams;

The weight of a 10% acid solution will be 21.9 / 0.1 = 219 grams.