Which of the following terms are present in the rate law?
A. The rate constant, the concentration of the reactants, and the order of the reactants
B. The rate constant and the concentration of the reactants
C. The rate constant and the temperature of the reactants
D. The rate constant, the temperature of the reactants, and the order of the products
To determine which of the terms are present in the rate law, we need to understand what the rate law represents. The rate law is an empirical equation that quantifies the relationship between the rate of a chemical reaction and the concentrations of the reactants. It is derived from experimental data.
The rate law generally takes the form:
Rate = k[A]^m[B]^n
Where:
- Rate is the reaction rate (usually expressed as the change in concentration per unit time)
- k is the rate constant, which represents the proportionality constant in the relationship
- [A] and [B] are the concentrations of the reactants A and B, respectively
- m and n are the reaction orders, which determine how the rate depends on the concentrations of the reactants
Based on this information, we can determine the terms present in the rate law:
A. The rate constant, the concentration of the reactants, and the order of the reactants - This choice is correct. The rate constant (k), the concentrations of the reactants ([A] and [B]), and the reaction orders (m and n) are all present in the rate law equation.
B. The rate constant and the concentration of the reactants - This choice is correct. The rate constant (k) and the concentrations of the reactants ([A] and [B]) are both present in the rate law equation.
C. The rate constant and the temperature of the reactants - This choice is incorrect. The rate constant (k) does not directly depend on the temperature of the reactants. However, the rate constant can vary with temperature due to the Arrhenius equation, but this relationship is not explicitly included in the rate law.
D. The rate constant, the temperature of the reactants, and the order of the products - This choice is incorrect. The rate constant (k) and the temperature of the reactants do not directly appear in the rate law equation. Additionally, the order of the products is not a term that appears in the rate law. The rate law only considers the concentrations of the reactants, not the products.
Therefore, the correct choices for the terms present in the rate law are A. The rate constant, the concentration of the reactants, and the order of the reactants, and B. The rate constant and the concentration of the reactants.