Question

What is the limiting reagent in the reaction: \( 2H_2 + O_2 \rightarrow 2H_2O \), if 3 moles of \( H_2 \) and 2 moles of \( O_2 \) are reacted together?

• A. \( H_2 \)
• B. \( O_2 \)
• C. Both are limiting reagents
• D. Neither is limiting

Hint:

The limiting reagent is the reactant that runs out first in a chemical reaction, limiting the amount of product that can be formed.

Answer 1

The Correct Option is A

To determine the limiting reagent, we compare the mole ratios of the reactants to the coefficients in the balanced equation.
The balanced equation is: \[ 2H_2 + O_2 \rightarrow 2H_2O \] From the equation, 2 moles of \( H_2 \) react with 1 mole of \( O_2 \).
- Given 3 moles of \( H_2 \), we need \( \frac{3}{2} = 1.5 \) moles of \( O_2 \) to completely react with it.
- Since 2 moles of \( O_2 \) are available, we have excess \( O_2 \), and \( H_2 \) is the limiting reagent.
Thus, \( H_2 \) is the limiting reagent.