Determine the volume of hydrogen (at a temperature of 25C and normal atmospheric pressure)

Determine the volume of hydrogen (at a temperature of 25C and normal atmospheric pressure), which will be released when dissolving 21.6 g of aluminum in an excess of dilute sulfuric acid.

Metallic aluminum interacts with sulfuric acid. This produces aluminum sulfate and bubbles of hydrogen gas. The reaction is described by the following equation.

2Al + 3H2SO4 = Al2 (SO4) 3 + 3 H2;

Let’s determine the chemical amount of aluminum. To do this, we divide its weight by the molar weight of the substance.

M Al = 27 grams / mol;

N Al = 21.6 / 27 = 0.8 mol;

The chemical amount of released hydrogen will be: 0.8 x 3/2 = 1.2 mol

Let’s calculate its volume.

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

V H2 = 1.2 x 22.4 = 26.88 liters;