How many liters of hydrogen can be obtained using 45.5 g of zinc and an excess of hydrochloric acid?

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 available chemical amount of zinc. To do this, divide the weight of pure metal by the weight of 1 mole of metallic zinc.

M Zn = 65 grams / mol; N Zn = 45.5 / 65 = 0.7 mol;

The same amount of hydrogen and zinc chloride salt will be synthesized.

Let’s calculate the volume of hydrogen. To do this, multiply the amount of substance by the volume of 1 mole of gas, which is 22.4 liters.

N H2 = 0.7 mol; V H2 = 0.7 x 22.4 = 15.68 liters;