Physical Chemistry

The study of energy transformations in chemical systems, governed by three fundamental laws that describe energy conservation, entropy increase, and the absolute zero of temperature. Thermodynamics determines whether a reaction is spontaneous through the Gibbs free energy.

The study of reaction rates, including how fast reactions occur and the step-by-step pathways (mechanisms) by which reactants transform into products. Rate laws express the mathematical relationship between concentration and reaction speed.

The application of quantum mechanics to chemical systems, explaining electronic structure, chemical bonding, and molecular properties by solving the Schr\u00f6dinger equation for atoms and molecules.

A thermodynamic potential ($G = H - TS$) that combines enthalpy and entropy to predict whether a process will occur spontaneously at constant temperature and pressure. A negative change in $G$ indicates a spontaneous process.

The minimum energy ($E_a$) that reactant molecules must possess for a chemical reaction to occur. It represents the energy barrier between reactants and products on a potential energy surface.

A thermodynamic quantity ($S$) that measures the dispersal of energy and the number of accessible microstates in a system. The Second Law of Thermodynamics states that the total entropy of an isolated system always increases.

The condition where two or more phases of a substance coexist in thermodynamic equilibrium, with no net transfer of matter between phases. Phase diagrams map the conditions of temperature and pressure at which phases are stable.

The state in which the rates of the forward and reverse reactions are equal, so the concentrations of reactants and products remain constant over time. The equilibrium constant $K$ quantifies the ratio of product to reactant concentrations.

The study of how matter interacts with electromagnetic radiation. Different types of spectroscopy (UV-Vis, IR, NMR, mass spectrometry) probe different molecular properties such as electronic transitions, molecular vibrations, and nuclear environments.

The study of chemical reactions that involve the transfer of electrons, particularly those occurring at electrode-solution interfaces. It encompasses both galvanic cells (which produce electricity) and electrolytic cells (which use electricity to drive reactions).