When 8 moles of lithium metal react with excess oxygen gas, how many moles of lithium oxide can be produced?

2li + o2 → li2o

2
4
8
16

From the balanced equation, we know that one mole of lithium oxide is produced for every two moles of lithium metal. Therefore, we have:
8 moles Lithium * (1 mole Li2O)/(2 moles Lithium) = 4 moles Li2O