AP Chemistry Speed Review

Introduction

Presenter: Jeremy Krug
Goal: Quick review of major AP Chemistry topics in under 20 minutes
Resources: Ultimate Review Packet offers more detailed study guides, longer review videos, and practice exams for $24.99 with potential discounts for classroom purchases

Mole Concept: Counts atoms/molecules; 1 mole = 6.022 x 10^23 particles
- Example: 1 mole of iron is 55.85 grams, 1 mole of water is 18.02 grams
Electron Configurations: Atoms are most stable with 8 valence electrons
- Example: Neon - 1s2, 2s2, 2p6
Coulomb’s Law: Attraction strength between opposite charges
- Greater magnitude of charge and closer distance increase attraction
- Applications in photoelectron spectroscopy
Periodic Table Patterns:
- Atomic radius: larger at the bottom/left
- First ionization energy: higher at top/right
- Formation of anions/cations: Anions (gain e-) get larger, cations (lose e-) get smaller

Bonds:
- Ionic: Metal + Nonmetal, electrostatic forces
- Covalent: Nonmetals share electrons
  - Polar: Unequal sharing
  - Nonpolar: Equal sharing
- Metallic: Electrons move freely in metals/alloys
Lewis Dot Diagrams: Visualize shapes and electron distribution
- Examples: Tetrahedral (109.5°), Linear (180°), Trigonal planar (120°)

Dispersion Forces: Weak, increase with molecule size/polarizability
Dipole-Dipole Forces: Stronger than dispersion, in polar molecules
Hydrogen Bonding: Strong, in molecules with O-H, N-H, F-H bonds
States of Matter:
- Solids: Fixed shape/volume
- Liquids: Flow, fixed volume
- Gases: Expand/compress easily
Ideal Gas Law: PV=nRT; approximates gas behavior
- Real gases deviate under certain conditions
Kinetic Energy & Temperature: Higher temperature = higher average kinetic energy
Concentration Measurement: Molarity (moles/solute divided by liters/solution)
Light and Matter: Interaction used in spectrophotometry for concentration analysis

Net Ionic Equations: Exclude spectator ions
Balancing Equations: Ensure atom count consistency using coefficients
Types of Reactions:
- Precipitation: Formation of solid in solution
- Redox: Electron transfer (oxidation/reduction)
- Acid-Base: Proton transfer, acid donates H+, base accepts H+
Stoichiometry: Mole ratio from balanced equations to calculate quantities

Relative Rates: Based on balanced equation coefficients
Rate Law: Experimentally determined, Rate = k[Reactant1]^order[Reactant2]^order...
- Zero/First/Second-Order Relationships
Integrated Rate Law: Calculate concentration over time
Reaction Mechanisms: Multi-step processes with a rate-determining slow step
Collision Theory: Reactions depend on energy/orientation of collisions
Catalysts: Lower activation energy, speed up reactions

Endothermic vs Exothermic: Absorb/release heat
Heat Transfer: Q = MC∆T
- Q (Joules), M (mass), C (specific heat capacity), ∆T (temperature change)
Enthalpy Change (∆H): Reaction heat change, estimated using bond enthalpies or formation enthalpies
Hess’s Law: Summing individual reaction enthalpies for overall reaction

Dynamic Equilibrium: Forward and reverse reactions at equal rates
Reaction Quotient (Q) & Equilibrium Constant (K): Determines reaction direction
- Large K: More product; Small K: More reactant
ICE Charts: Initial, Change, Equilibrium concentrations for solving equilibrium problems
Le Chatelier’s Principle: Predicts reaction shift due to changes; only temperature changes K

pH and pOH:
- pH = -log[H+], pOH = -log[OH-]
- pH + pOH = 14 at 25°C
- [H+][OH-] = 1 x 10^-14 at 25°C (Kw)
Strong vs Weak Acids/Bases: Complete vs partial ionization
Acid-Base Titrations: Find unknown concentration, endpoints identified by indicator
- Titration curve inflection point = equivalence point
Buffers: Resist pH changes, use Henderson-Hasselbalch equation for pH calculation

Entropy (S): Disorder measurement, increases from solid to gas
Gibbs Free Energy (ΔG): Determines thermodynamic favorability
- ΔG = ΔH - T∆S; negative ΔG is favorable
- ΔG related to equilibrium constant K: ΔG = -RTlnK
Electrochemistry: Galvanic cells, electron flow, salt bridges
- Anode (oxidation) and Cathode (reduction)
- Calculate cell voltage using standard reduction potentials
- Use Nernst Equation for non-standard conditions
Electrolysis: Uses external electricity to drive non-spontaneous reactions
- I = Q/t; relate coulombs to quantity of material plated

Conclusion: