How much aluminum is required for the reaction with hydrochloric acid, taken in excess, to obtain 5.6 liters of hydrogen.

Aluminum reacts violently with hydrochloric acid. In this case, an aluminum chloride salt is formed and elemental hydrogen is released. The interaction is described by the following chemical equation.

Al + 3HCl = AlCl3 + 3/2 H2;

Let’s calculate the chemical amount of the evolved hydrogen gas.

To do this, we find the ratio of its volume to the volume of 1 mole of gas (filling a space with a volume of 22.4 liters).

N H2 = 5.6 / 22.4 = 0.25 mol;

To obtain such an amount of hydrogen, it is required to dissolve 0.25 x 2/3 = 0.1666 mol of aluminum.

Let’s calculate its weight.

M Al = 27 grams / mol;

m Al = 27 x 0.1666 = 4.5 grams;