Final answer:
In a chemical reaction, the limiting reagent is the substance that will be consumed first and limits the amount of product formed. To identify it, compare the stoichiometric mole ratios from the balanced chemical equation to the moles of reactants present. The reactant that produces the least amount of product is the limiting reagent.
Step-by-step explanation:
The subject of this question is Chemistry and is typically addressed at the High School level. The concept being explored is limiting reagents, which are substances that determine the amount of product that can be formed in a chemical reaction. To identify the limiting reagent, one must start by writing a balanced chemical equation and then calculating the moles of reactants available. If the question alludes to the reaction of forming N₂O₄ from N₂ and O₂, based on the stoichiometry of the balanced equation N₂ + 2 O₂ → N₂O₄, the reactant that produces the least amount of product is the limiting reagent.
As per one of the given examples, if a chemist were to react three moles of N₂ with six moles of H₂ to produce ammonia (NH3), the limiting reagent could be determined by comparing the mole ratio required by the balanced chemical equation. Since the balanced equation for ammonia formation is N₂ + 3H₂ → 2NH3, it can be seen that three moles of hydrogen react with one mole of nitrogen to make two moles of ammonia. Therefore, in this scenario, nitrogen would be the limiting reagent because three moles of N₂ would require nine moles of H₂ to completely react, but only six moles of H₂ are available.