Final answer:
To produce 4 moles of H₂O, 2 moles of O₂ are required according to the balanced chemical equation 2 H₂(g) + O₂(g) → 2 H₂O(g), which shows a 2:1 mole ratio between H₂O and O₂.
Step-by-step explanation:
To determine how many moles of O2 would be required to produce 4.0 moles of H₂O, we look at the balanced chemical equation for the reaction:
2 H₂(g) + O₂(g) → 2 H₂O(g)
From the equation, we can see that 2 moles of hydrogen gas (H₂) react with 1 mole of oxygen gas (O₂) to produce 2 moles of water (H₂O).
Therefore, the mole ratio of H₂O to O₂ is 2:1.
Using this ratio, we find that 1 mole of O₂ produces 2 moles of H₂O.
Hence, to produce 4 moles of H₂O, we would need half the amount of O₂ moles, which is 2 moles of O₂.