Q

QuestionChemistry

The concept of a limiting reactant is best described by option B: "It is the reactant that remains when the reaction is complete." Explanation: When a chemical reaction occurs, reactants are consumed and products are formed. However, the amount of products created depends on the amount of available reactants. If one reactant is present in excess, the reaction will continue until the other reactant, known as the limiting reactant, is entirely consumed. At this point, even if there's still some excess reactant left, no more products will be formed because the reaction has reached its limit, determined by the amount of the limiting reactant.

Let's analyze the other options to understand why they are not the best descriptions of a limiting reactant: A. "It is the reactant that determines the amount of product formed." While this statement is true, it does not fully capture the essence of a limiting reactant. Any reactant can determine the amount of product formed, depending on which one is present in a lesser amount. C. "It is the reactant that has the smallest mass." This statement is incorrect because the mass of a reactant does not necessarily determine if it is a limiting reactant. It is the amount of a reactant relative to the other reactants that matters. D. "It is the reactant that reacts the fastest." This statement is also incorrect because the reaction rate does not determine if a reactant is limiting. Instead, it is the relative amount of a reactant compared to the other reactants that defines the limiting reactant.