Calculate the amount of hydrogen required to dissolve 7.2 g of magnesium in hydrochloric acid.

Calculate the amount of hydrogen required to dissolve 7.2 g of magnesium in hydrochloric acid. Calculate the mass of the salt formed.

Metallic magnesium dissolves in hydrochloric acid solution. The chemical reaction proceeds according to the following equation:

Mg + 2HCl = MgCl2 + H2 ↑;

Let us determine the molar amount of a substance of metallic magnesium.

To do this, we divide its mass by the weight of 1 mole of metallic magnesium.

M Mg = 24 grams / mol;

N Mg = 7.2 / 24 = 0.3 mol;

An equivalent amount of hydrogen gas and salt will be obtained.

Let’s calculate the volume of hydrogen.

For this purpose, we multiply the amount of substance by the volume of 1 mole of gas (filling volume 22.4 liters).

V H2 = 0.3 x 22.4 = 6.72 liters;

Let’s calculate the weight of magnesium chloride.

To do this, we multiply the chemical amount of the substance by the weight of 1 mole of salt.

M MgCl2 = 24 + 35.5 x 2 = 95 grams / mol;

m MgCl2 = 0.3 x 95 = 28.5 grams;