Calculate the mass of aluminum oxide that can be obtained by burning 135 g of aluminum powder.

The oxidation reaction of aluminum with atmospheric oxygen is described by the following chemical reaction equation:

4Al + 3O2 = 2Al2O3;

The aluminum oxide molecule contains two aluminum atoms, therefore, from two moles of aluminum, only one mole of aluminum oxide can be obtained.

Determine the amount of substance that is contained in a sample of 135 grams of metal:

N Al = 135/27 = 5 mol;

The amount of metal oxide substance will be:

N Al2O3 = N Al / 2 = 5/2 = 2.5 mol;

Let’s calculate the weight of this amount of metal oxide:

To do this, we multiply the amount of the substance by its molar mass.

M Al2O3 = 27 x 2 + 16 x 3 = 102 grams / mol;

The weight of the oxide will be:

m Al2O3 = 2.5 x 102 = 255 grams;