Question

Which steps are followed to calculate the mass of oxygen (O2) that will react completely with 48.0 grams of aluminum (Al)?

Answer 1

- First of all, think the reaction:

4Al + 3O₂ → 2Al₂O₃

- Afterwards, determine the ratio of reactants (4:3)

4Al + 3O₂ → 2Al₂O₃

- Convert the mass of Al into moles, by dividing mass / molar mass

48 g / 26.98 g/m = 1.78 mol

- Make a rule of three to determine the moles of O₂

4 mol of Aluminum react with 3 mol of oxygen, so

1.78 mol of Al, will react with (1.78 . 3) / 4 = 1.33 mol of O₂

- Finally, convert the moles in mass like this:

Mol . molar mass = mass → 1.33 mol . 32 g/m = 42.7 grams

Step-by-step explanation:

Reaction

4Al + 3O₂ → 2Al₂O₃