Concept:The limiting reactant determines the definitive endpoint of a chemical reaction. It is the chemical "bottleneck" that runs out first.
Formula:$$ \text{Amount of Limiting Reactant at Completion} = 0 $$
Solution:- Because the limiting reactant is entirely consumed to produce the theoretical yield, there is none of it left over when the reaction stops.
- Therefore, by definition, the limiting reactant is the chemical species which is not in excess.
Why other options are incorrect:- Option A: This perfectly describes the "excess reactant," which is the exact opposite of the limiting reactant.
- Option C & D: These statements describe a catalyst or a spectator ion. Limiting reactants are definitively consumed as primary chemical participants in the reaction.
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