K[A]^m[B]^n

Definition

k[A]^m[B]^n is a mathematical expression used to represent the rate law in chemical kinetics. The rate law describes the relationship between the reaction rate and the concentrations of the reactants involved in the reaction.

5 Must Know Facts For Your Next Test

1. The exponents 'm' and 'n' in the expression k[A]^m[B]^n represent the reaction orders with respect to the reactants A and B, respectively.
2. The rate constant 'k' is a measure of the intrinsic reactivity of the reactants and is affected by factors such as temperature, pressure, and the presence of catalysts.
3. The overall reaction order is the sum of the individual reaction orders, which can be determined experimentally or predicted based on the mechanism of the reaction.
4. The rate law can be used to predict the rate of a reaction at any given set of reactant concentrations, and it is an essential tool in the study of chemical kinetics.
5. The values of the exponents 'm' and 'n' in the rate law expression can be determined through experimental observations or by analyzing the reaction mechanism.

Review Questions

• Explain the relationship between the rate law expression k[A]^m[B]^n and the reaction orders with respect to the reactants A and B.
  • The exponents 'm' and 'n' in the rate law expression k[A]^m[B]^n represent the reaction orders with respect to the reactants A and B, respectively. The reaction order is the power to which the concentration of a reactant is raised in the rate law equation. This means that the rate of the reaction is proportional to the concentration of A raised to the power of 'm' and the concentration of B raised to the power of 'n'. The overall reaction order is the sum of the individual reaction orders, which can be determined experimentally or predicted based on the mechanism of the reaction.
• Describe how the rate constant 'k' in the expression k[A]^m[B]^n is affected by various factors and its importance in understanding chemical kinetics.
  • The rate constant 'k' in the expression k[A]^m[B]^n is a measure of the intrinsic reactivity of the reactants and is affected by factors such as temperature, pressure, and the presence of catalysts. An increase in temperature, for example, typically leads to an increase in the rate constant, as it provides more energy for the reactants to overcome the activation barrier and form products. The rate constant is an essential parameter in the study of chemical kinetics, as it allows for the prediction of the rate of a reaction at any given set of reactant concentrations. Understanding the factors that influence the rate constant is crucial for optimizing reaction conditions and designing more efficient chemical processes.
• Analyze how the values of the exponents 'm' and 'n' in the rate law expression k[A]^m[B]^n can be determined and their significance in understanding the reaction mechanism.
  • The values of the exponents 'm' and 'n' in the rate law expression k[A]^m[B]^n can be determined through experimental observations or by analyzing the reaction mechanism. These exponents represent the reaction orders with respect to the reactants A and B, respectively, and provide valuable insights into the underlying mechanism of the chemical reaction. By understanding the reaction orders, researchers can infer the elementary steps involved in the reaction and the rate-determining step, which is the slowest step that controls the overall rate of the reaction. The reaction orders can also be used to predict the effect of changes in reactant concentrations on the reaction rate, allowing for the optimization of reaction conditions and the development of more efficient chemical processes.

Related terms

Rate Law: The rate law is an equation that describes the relationship between the rate of a chemical reaction and the concentrations of the reactants.

Reaction Order: The reaction order is the power to which the concentration of a reactant is raised in the rate law expression.

Rate Constant: The rate constant, represented by the symbol 'k', is a proportionality constant that relates the rate of a reaction to the concentrations of the reactants.