Calculate the mass of hydrogen gas that is released if you dissolve 4.5 g of aluminum in hydrochloric acid.

Metallic aluminum interacts with hydrochloric acid. At the same time, the salt of aluminum chloride is synthesized and bubbles of hydrogen gas are released. The reaction is described by the following equation.

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

Let’s calculate the chemical amount of aluminum. For this purpose, we divide its weight by the molar weight of the substance.

M Al = 27 grams / mol;

N Al = 4.5 / 27 = 0.1666 mol;

The chemical amount of released hydrogen will be: 0.1666 x 3/2 = 0.25 mol

Let’s determine its weight.

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

M H2 = 2 grams / mol;

m H2 = 0.1666 x 2 = 0.333 grams;