Part III: Chemical Kinetics
Chapters 9â12
This part explores the rates and mechanisms of chemical reactions. Beginning with empirical rate laws and integrated rate expressions, we develop the theoretical frameworks â collision theory, transition state theory, and enzyme kinetics â that explain why reactions proceed at the rates they do and how temperature, catalysts, and molecular structure influence reactivity.
Part Overview
Chemical kinetics is the study of reaction rates and the molecular-level events that govern how fast chemical transformations occur. While thermodynamics tells us whether a reaction is favorable, kinetics tells us how quickly equilibrium is reached. This part builds from experimental rate laws through the theoretical models that connect macroscopic rates to microscopic molecular behavior.
Key Topics
- ⢠Zero-order, first-order, and second-order rate laws
- ⢠Integrated rate expressions and half-life relationships
- ⢠Determining reaction order from experimental data
- ⢠Arrhenius equation and activation energy
- ⢠Collision theory and steric factors
- ⢠Transition state theory and the Eyring equation
- ⢠Potential energy surfaces and reaction coordinates
- ⢠MichaelisâMenten enzyme kinetics
- ⢠LineweaverâBurk analysis and enzyme inhibition
4 chapters | Rate laws to enzyme kinetics | Full derivations
Key Equations
First-Order Integrated Rate Law
$$[\text{A}] = [\text{A}]_0 \, e^{-kt}$$
Second-Order Integrated Rate Law
$$\frac{1}{[\text{A}]} = \frac{1}{[\text{A}]_0} + kt$$
Arrhenius Equation
$$k = A \, e^{-E_a / RT}$$
Eyring Equation
$$k = \frac{k_B T}{h} \, e^{-\Delta G^\ddagger / RT}$$
General Rate Law
$$r = k[\text{A}]^m[\text{B}]^n$$
MichaelisâMenten Equation
$$v = \frac{V_{\max}[\text{S}]}{K_M + [\text{S}]}$$
Chapters
Chapter 9: Reaction Rate Laws
Empirical rate laws, reaction order, integrated rate expressions for zero-, first-, and second-order reactions, half-life relationships, and experimental methods for determining rate laws from concentrationâtime data.
Chapter 10: Arrhenius & Collision Theory
Temperature dependence of rate constants, the Arrhenius equation, activation energy, pre-exponential factors, collision theory derivation, steric factors, and the relationship between molecular collisions and macroscopic reaction rates.
Chapter 11: Transition State Theory
The activated complex, potential energy surfaces, reaction coordinates, the Eyring equation, thermodynamic formulation of rate constants, and the connection between Gibbs energy of activation and reaction rates.
Chapter 12: Enzyme Kinetics
The MichaelisâMenten mechanism, steady-state approximation, LineweaverâBurk plots, enzyme inhibition (competitive, uncompetitive, noncompetitive), catalytic efficiency, and the role of enzymes in biological reaction rates.