Reaction Mechanisms & Energy Profiles

Explore multi-step reaction mechanisms where elementary steps combine to give the overall reaction. Identify intermediates (produced then consumed), catalysts (consumed then regenerated), and the rate-determining step (slowest step with highest activation energy). Visualize energy profiles showing multiple transition states and understand how the mechanism must match the experimentally determined rate law.

REACTION MECHANISMS

Sequence of elementary steps that collectively describe a chemical change.

CORE FORMULAS

Rate of elementary step

AP EXAM CONNECTION

Unit: Unit 5: Kinetics
Learning Objective: ENE-1.H

COMMON MISCONCEPTIONS

Rate law must match the overall equation.

KEY TAKEAWAYS

The slowest step is the rate-determining step.

DEEP DIVE: RELATED CONCEPTS

COLLISION THEORY

Collisions must have sufficient energy and proper orientation for a reaction to occur....

RELATED VISUALIZATIONS

AP CHEMISTRY

First-Order Kinetics Decay

Analyze first-order reactions where the rate depends linearly on one reactant concentration: rate = k[A]. Visualize exponential decay using the integrated rate law ln[A]t = ln[A]₀ - kt, and understand that first-order reactions have constant half-life t₁/₂ = 0.693/k independent of initial concentration. Explore applications in radioactive decay, drug metabolism, and chemical decomposition reactions.

2,979 views

AP CHEMISTRY

Photoelectron Spectroscopy (PES)

Interpret photoelectron spectroscopy (PES) data to determine electron configuration and relative energies of electrons in different orbitals. Analyze PES spectra where peak position indicates binding energy (related to Coulomb's law and effective nuclear charge) and peak height represents the number of electrons. Practice identifying elements from their PES spectra and understanding how core versus valence electrons produce distinct peaks.

2,948 views

AP CHEMISTRY

Gas Laws

Explore the fundamental gas laws that describe relationships between pressure, volume, temperature, and amount of gas. Visualize Boyle's Law (P₁V₁ = P₂V₂), Charles's Law (V₁/T₁ = V₂/T₂), Gay-Lussac's Law (P₁/T₁ = P₂/T₂), Avogadro's Law (V₁/n₁ = V₂/n₂), and the Combined Gas Law. Understand how these individual laws combine to form the Ideal Gas Law PV = nRT.

2,377 views

AP CHEMISTRY

Electron Configuration

Build electron configurations for atoms and ions using the Aufbau principle, Hund's rule, and the Pauli exclusion principle. Visualize how electrons fill orbitals in order of increasing energy (1s, 2s, 2p, 3s, 3p, 4s, 3d...), understand noble gas notation shortcuts, and identify valence electrons. Explore exceptions like chromium and copper, and connect electron configuration to periodic trends and chemical reactivity.

2,254 views