Final answer:
In the reaction between hydrogen and oxygen to form water, the maximum number of moles of water that can be formed from 1.9 moles of hydrogen and 3.0 moles of oxygen is 1.5 moles.
Step-by-step explanation:
To determine how many moles of water can be formed from 1.9 moles of H₂ and 3.0 moles of O₂, we need to look at the balanced chemical equation for the reaction:
2H₂(g) + O₂(g) → 2H₂O(g)
The stoichiometric ratio tells us that 2 moles of H₂ react with 1 mole of O₂ to produce 2 moles of H₂O.
Therefore, if we have 1.9 moles of H₂ and 3.0 moles of O₂, we have an excess of H₂ because it would require only 1.5 moles of O₂ to react with 1.9 moles of H₂.
So, the maximum number of moles of H₂O that can be formed is 1.5 moles.