How much zinc is required to react with excess hydrochloric acid to produce 5.6 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 released amount of hydrogen. To do this, we divide the volume of synthesized hydrogen by the volume of 1 mole of gas, which is 22.4 liters.

V H2 = 5.6 liters; N H2 = 5.6 / 22.4 = 0.25 mol;

To synthesize such an amount of hydrogen, it is necessary to take the same amount of zinc. Let’s calculate its weight.

M Zn = 65 grams / mol;

m Zn = 0.25 x 65 = 16.25 grams;