What mass of a solution of hydrochloric acid with a mass fraction of 15% must be taken for the reaction

What mass of a solution of hydrochloric acid with a mass fraction of 15% must be taken for the reaction with zinc in order to release 67.2 liters of hydrogen?

In order to obtain a given molar amount of hydrogen, it is necessary to take twice the molar amount of hydrogen chloride. This is due to the fact that there are two hydrogen atoms in the molecule, and one hydrogen atom in the hydrochloric acid molecule:

Zn + 2HCl → ZnCl2 + H2;

Let’s find the chemical amount of synthesized hydrogen.

N H2 = 67.2 / 22.4 = 3 mol;

To get this amount of hydrogen, you need to take 3 x 2 = 6 mol of hydrochloric acid.

Let’s calculate its weight.

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

m HCl = 6 x 36.5 = 219 grams;

The weight of a 15% acid solution will be: 219 / 0.15 = 1 460 grams;