Concept:To identify the limiting reactant, divide the provided number of moles for each reactant by its respective stoichiometric coefficient from the balanced equation. The smallest result limits the reaction.
Formula:$$ \text{Ratio} = \frac{\text{Available Moles}}{\text{Coefficient}} $$
Solution:- We are given 5 moles of \( \text{H}_2 \) and 5 moles of \( \text{O}_2 \).
- For Hydrogen (\( \text{H}_2 \)): Coefficient is 2. Ratio = \( 5 / 2 = 2.5 \).
- For Oxygen (\( \text{O}_2 \)): Coefficient is 1. Ratio = \( 5 / 1 = 5.0 \).
- Since 2.5 is significantly smaller than 5.0, Hydrogen (\( \text{H}_2 \)) will be entirely consumed first, making it the Limiting Reagent.
Why other options are incorrect:- \( \text{O}_2 \) is limiting: Incorrect; Oxygen is in heavy excess. It only takes 2.5 moles of Oxygen to react with 5 moles of Hydrogen, leaving 2.5 moles of Oxygen completely unreacted.
- \( \text{H}_2 \) is excess: Incorrect, it is entirely consumed.
- No limiting reagent: This would only be true if they were provided in a perfect 2:1 stoichiometric ratio (e.g., 4 moles of \( \text{H}_2 \) and 2 moles of \( \text{O}_2 \)).
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