Find the volume of gas released when an excess of magnesium is exposed to 80 g

Find the volume of gas released when an excess of magnesium is exposed to 80 g of hydrochloric acid with a mass fraction of hydrogen chloride of 20%.

Magnesium interacts with hydrochloric acid. In this case, magnesium chloride is synthesized and hydrogen gas is released. This reaction is described by the following chemical reaction equation:

Mg + 2HCl = MgCl2 + H2;

In accordance with the coefficients of the equation, in the reaction of 2 mol of acid, 1 mol of hydrogen gas is released.

Let’s calculate the chemical amount of the acid. To do this, divide its weight by the weight of 1 mole of acid.

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

N HCl = 80 x 0.2 / 36.5 = 0.438 mol;

During the reaction, half the amount of hydrogen will be synthesized.

Let’s calculate its volume, for this we multiply the amount of substance by the volume of 1 mole of gas (22.4 liters):

V H2 = 0.438 / 2 x 22.4 = 4.906 liters;