Chemistry

Electrochemistry and organic basics

Oxidation numbers, cells, Nernst, functional groups.

Basics

Oxidation and reduction

Oxidation is loss of electrons (oxidation number up); reduction is gain. An oxidizing agent oxidizes something else and is itself reduced. Balance half-reactions so electrons cancel, then add.

Galvanic cell

A spontaneous redox reaction drives current. Oxidation at the anode, reduction at the cathode. A salt bridge keeps charge balance. Electrolysis is the reverse: an external voltage forces a non-spontaneous reaction.

Organic skeleton

A carbon chain or ring; functional groups set the chemistry. Alkane (single), alkene (double), alkyne (triple), alcohol (–OH), carboxylic acid (–COOH), amine (–NH₂). Isomers share a formula but differ in connectivity or stereo arrangement.

Formulas

Cell potential

E°_cell = E°_cathode − E°_anode (환원 전위 표)

E°>0 means spontaneous under standard conditions. Tables are usually reduction potentials.

Symbols

E° standard reduction potential

Nernst equation

E = E° − (RT / nF) ln Q ≈ E° − (0.059 V / n) log₁₀ Q (25 °C)

When concentrations are not standard. n is moles of electrons transferred.

Symbols

Q reaction quotient
F Faraday constant
n electron count

Faraday electrolysis

m = (M / n F) I t

Charge I t sets the mass deposited.

Symbols

I current
t time
M molar mass

Key table

F	about 96485 C/mol
Hydrocarbons	CₙH₂ₙ₊₂ alkane (acyclic), CₙH₂ₙ alkene or cycloalkane

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.

Nuclear chemistry

Radioactivity, half-life, binding energy.

Solutions and kinetics

Concentration, colligative properties, rate laws.

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.