Chemistry

Solutions and kinetics

Concentration, colligative properties, rate laws.

Basics

Solutions

Molarity M is moles of solute per litre of solution. Molality m is moles per kg of solvent — steadier with temperature. Dilution: M₁V₁=M₂V₂. Colligative effects (vapor lowering, boiling up, freezing down, osmosis) track particle count (van ’t Hoff i).

Rates

Rate depends on concentration, temperature, catalysts, and surface. The rate law is experimental. Heat raises collisions and the fraction that clear the barrier (Arrhenius). A catalyst opens a path with lower E_a.

Formulas

Rate law (example)

rate = k [A]^m [B]^n

m, n are experimental orders. k is the rate constant.

Symbols

k rate constant

Arrhenius

k = A e^{−E_a / RT}

A larger E_a makes k more temperature-sensitive.

Symbols

E_a activation energy
A pre-exponential factor

Osmotic pressure (ideal)

Π = i M R T

van ’t Hoff. A sketch for cells and reverse osmosis.

Symbols

i van ’t Hoff factor

In this field

Atoms and the periodic table

Atomic structure, nucleus and electrons, periods and groups.

Chemical bonding

Ionic, covalent, and metallic bonds, plus molecular shape.

The mole and stoichiometry

Moles, molar mass, empirical formulas, and yield.

Gases and acids–bases

Ideal gas, pH, and buffers.

Thermo, equilibrium, kinetics

Enthalpy, Gibbs energy, K, and rate laws.

Electrochemistry and organic basics

Oxidation numbers, cells, Nernst, functional groups.

Nuclear chemistry

Radioactivity, half-life, binding energy.

Analytical chemistry

Titration, spectroscopy, and chromatography — measuring what is present and how much.

Polymers and solids

Crystals and glasses, metal–ionic–covalent solids, polymer chains and the glass transition.

Coordination compounds

Ligands, coordination number, crystal field, colour, and an 18-electron sketch.

Electrochemical cells

Galvanic versus electrolytic, Nernst, Faraday, and a corrosion sketch.

Phase equilibria and diagrams

Gibbs phase rule, unary diagrams, eutectics, and the lever rule.