How many moles of al2o3 are formed when 0.78 mol o2 reacts with aluminum?

The balanced chemical equation is:

4 Al + 3 O₂ → 2 Al₂O₃

3 moles of oxygen - - - gives--> 2 moles of Al₂O₃

0.78 mol of O₂ - - - gives--->? moles of Al₂O₃

So the number of moles of Al₂O₃ = (0.78 x 2) / 3 = 0.52 mole