Question

If 45.3 grams of aluminum react with an excess of oxygen, as shown in the balanced chemical equation below, how many grams of aluminum oxide can be formed?

4Al + 3O2 2Al2O3

Answer 1

Follow the steps in this example.
http://www.jiskha.com/science/chemistry/stoichiometry.html

Answer 2

1. 4Al + 3O2 = 2Al2O3
2. Set the equation. mol ratio is 4:2
45.3 g Al * (1 mol Al / 26.982 g Al) * (2 mol AlO / 4 mol Al) * (101.964 g AlO / 1 mol AlO)
= 85.63 g Al2O3