Question

In the reaction \( \mathrm{2H_2 + O_2 \rightarrow 2H_2O} \), if 4 moles of hydrogen react completely with oxygen, how many moles of water will be produced?

• A. 2 mol
• B. 4 mol
• C. 8 mol
• D. 1 mol

Hint:

Always use the mole ratio from the balanced chemical equation to solve stoichiometry problems.

Answer 1

The Correct Option is B

Based on the stoichiometric equation: \[ \mathrm{2H_2 + O_2 \rightarrow 2H_2O} \] A molar ratio of 2:2 (hydrogen to water) exists. Therefore, 4 moles of hydrogen will yield: \[ \frac{2 \text{ mol } \mathrm{H_2O}}{2 \text{ mol } \mathrm{H_2}} \times 4 \text{ mol } \mathrm{H_2} = 4 \text{ mol } \mathrm{H_2O} \]