In the reaction: 2H₂ + O₂ → 2H₂O, if 5 moles of H₂ and 2 moles of O₂ are mixed, the limiting reagent is:

Correct option is D

The correct answer is: (d) O₂

Explanation:

• Balanced equation: 2H₂ + 1O₂ → 2H₂O

• From the equation, 2 moles of H₂ react with 1 mole of O₂.

• Given:

  • H₂ = 5 moles

  • O₂ = 2 moles

To fully react with 5 moles of H₂, we would need:
→ (1 mol O₂ / 2 mol H₂) × 5 mol H₂ = 2.5 moles of O₂

But only 2 moles of O₂ are available.
Hence, O₂ is the limiting reagent (it will be used up first and limit the amount of product formed).

Information Booster:

• Limiting reagent determines the maximum amount of product that can be formed.

• Excess reagent remains unreacted.

• Identifying the limiting reagent is crucial in yield calculations.

• This concept is essential in stoichiometry and industrial chemical processes.

• After the limiting reagent is consumed, the reaction stops.

• Theoretical yield is based only on the amount of the limiting reagent.