Final answer:
The limiting reactant in the reaction of calcium and oxygen is oxygen, and the reaction will produce 6 moles of calcium oxide.
Step-by-step explanation:
When 3 moles of calcium react with 3 moles of oxygen, we must first write the balanced chemical equation for the reaction to determine the limiting reactant and the moles of calcium oxide formed.
The balanced equation for the formation of calcium oxide is:
2 Ca (s) + O2 (g) → 2 CaO (s)
This tells us that two moles of calcium react with one mole of oxygen to produce two moles of calcium oxide. Therefore, the mole ratio of calcium to oxygen required is 2:1.
Given:
- 3 moles of calcium (Ca)
- 3 moles of oxygen (O2)
Since the reaction requires two moles of calcium for every one mole of oxygen, having 3 moles each of calcium and oxygen means calcium is in excess and oxygen is actually the limiting reactant as it gets fully consumed first.
Because we have 3 moles of oxygen, they will react completely with 6 moles of calcium (based on the 2:1 ratio), leaving excess calcium unreacted. Therefore, we can form:
3 mol O2 × (2 mol CaO / 1 mol O2) = 6 mol CaO
6 moles of calcium oxide are formed.