Physical Chemistry & Thermochemistry

The laws of thermochemistry are used to describe the heat or energy flow of chemical reactions. Understanding the values of a reaction's enthalpy will help determine whether the reaction is endothermic or exothermic.

Values of thermodynamic quantities are commonly expressed for standard state conditions, so it is a good idea to understand what the standard state conditions are.

This is a step-by-step worked problem to help you calculate bond energies and enthalpies for gaseous reactions.

This is a set of worked thermochemistry problems for calculating the change in enthalpy. Links are given to rules of thermochemistry and explanations of endothermic and exothermic reactions.

These are examples of how to calculate the heats of formation for compounds and ions in aqueous solution.

Learn about endothermic and exothermic chemical reactions and get instructions to perform your own hot and cold chemistry demonstrations.

Here's an endothermic reaction demonstration that is easy to do and cold enough to freeze water.

This is a table of molar heats of formation for common anions and cations in aqueous solution.

Certain rules or laws apply to thermochemical equations and enthalpy. These are explanations and examples of these laws, including Hess's Law.

A calorimeter is a device used to measure the quantity of heat flow in a chemical reaction. Learn about two of the most common types of calorimeters, the coffee cup calorimeter and the bomb calorimeter, and find out how to use them to calculate heat flow and enthalpy change.

The Nernst equation is used to calculate the voltage of an electrochemical cell or to find the concentration of one of the components of the cell. Here is a look at the Nernst equation and an example of how to apply it to solve a problem.

Learn how to calculate the energy change in a nuclear reaction, such as radioactive decay.

This is a table of single bond energies in units of kJ/mol at 25°C. Use these values to predict whether a reaction will be endothermic or exothermic and to calculate change in enthalpy for gases.

Learn about absolute zero and the Kelvin and Celsius temperature scales.

Boyle's Law describes the relationship between pressure and volume of an ideal gas when mass and temperature are held constant.

Charles' Law describes the relationship between temperature and volume of an ideal gas when mass and pressure are held constant.

Free databases with thermophysical properties of materials. Select "Thermal Data" from the navigation bar on the left.

Abstracts and Tables of Contents.

Includes thermodynamics, quantum mechanics, and structure of the nucleus. From Carl R. Nave, Georgia State University.

Calculation of gas density and specific volume for a given compressibility factor.

Online calculation of the properties of moist air in SI units (Java). There's also a version with English units.

Lucid treatment of chemical kinetics, bonding, and activation energy by Frank L. Lambert, Occidental College. For more on entropy, see his Entropy and the Second Law of Thermodynamics, which includes treatment of the Gibbs free energy equation.

Using quantum mechanics to predict chemical structure. From Richard F. W. Bader, McMaster University, Hamilton, Ontario.

Accurate thermophysical properties for 16 fluids: density, specific volume, Cp, Cv, enthalpy, internal energy, entropy, sound speed. From the NIST Standard Reference Database Number 69 - March 1998 Release.

From the University of Oregon, online experiments (Java applet) demonstrating the diffusion process which occurs when gases of different temperatures are mixed.