Writing Rate Laws of Reaction Mechanisms Using The Rate Determining Step - Chemical Kinetics

Reaction Mechanisms

• Definition: A reaction mechanism is a step-by-step pathway through which a chemical reaction occurs.

• Elementary Reaction: Each individual step within a reaction mechanism is referred to as an elementary reaction.

Example of a Reaction Mechanism

• Step 1:

  • Reaction: A + B → C + D

  • Indicated as Step 1

• Step 2:

  • Reaction: D + E → F + B

  • Represents the second step of the reaction.

• Overall Mechanism: The combination of both steps (Step 1 and Step 2) constitutes the complete reaction mechanism.

Rate Law Expression

• The rate law expression can be derived for each elementary reaction based on the coefficients of the reactants in that specific step.

• Coefficients in the balanced chemical equation correspond to the order with respect to each reactant in the rate law.