**Correct Option: C (4 moles)** ### Step-by-Step Explanation: 1. **Understanding the Reaction**: The chemical reaction given is: \[ 2 \text{H}_2 + \text{O}_2 \rightarrow 2 \text{H}_2\text{O} \] This equation tells us that 2 moles of hydrogen gas (H₂) react with 1 mole of oxygen gas (O₂) to produce 2 moles of water (H₂O). 2. **Identifying the Stoichiometry**: From the balanced equation, we can see the stoichiometric ratios: - 2 moles of H₂ produce 2 moles of H₂O. - This means that for every 2 moles of hydrogen gas consumed, 2 moles of water are produced. 3. **Scaling Up the Reaction**: If we have 4 moles of hydrogen gas (H₂), we can determine how many moles of water (H₂O) will be produced by using the stoichiometric ratio from the balanced equation: - Since 2 moles of H₂ produce 2 moles of H₂O, we can set up a proportion: \[ \text{If } 2 \text{ moles of H}_2 \rightarrow 2 \text{ moles of H}_2\text{O} \] \[ \text{Then } 4 \text{ moles of H}_2 \rightarrow X \text{ moles of H}_2\text{O} \] 4. **Calculating the Amount of Water Produced**: To find \(X\), we can use the ratio: \[ \frac{2 \text{ moles of H}_2}{2 \text{ moles of H}_2\text{O}} = \frac{4 \text{ moles of H}_2}{X \text{ moles of H}_2\text{O}} \] Cross-multiplying gives: \[ 2X = 4 \implies X = \frac{4}{2} = 2 \] However, since we are doubling the amount of hydrogen, we can also see that: \[ 4 \text{ moles of H}_2 \rightarrow 4 \text{ moles of H}_2\text{O} \] 5. **Final Conclusion**: Therefore, when 4 moles of hydrogen gas are completely consumed, **4 moles of water** are produced. ### Why Other Options Are Incorrect: - **Option A (1 mole)**: This option suggests that only 1 mole of water is produced, which is incorrect based on the stoichiometry of the reaction. The reaction clearly shows that 2 moles of H₂ produce 2 moles of H₂O, so 4 moles of H₂ would produce 4 moles of H₂O. - **Option B (2 moles)**: This option implies that only 2 moles of water are produced from 4 moles of hydrogen gas. This is also incorrect because, according to the stoichiometric ratio, 4 moles of H₂ would yield 4 moles of H₂O. - **Option D (6 moles)**: This option suggests that 6 moles of water are produced, which exceeds the amount that can be produced from the given amount of hydrogen gas. The reaction does not support this, as the maximum yield from 4 moles of H₂ is 4 moles of H₂O. ### Revision Summary: - The balanced reaction shows that 2 moles of H₂ produce 2 moles of H₂O. - Doubling the amount of H₂ (from 2 to 4 moles) results in doubling the amount of H₂O produced (from 2 to 4 moles). - Always refer to the stoichiometric coefficients in a balanced equation to determine the relationships between reactants and products. - Ensure to check each option against the stoichiometry to avoid common pitfalls in calculations.