This Demonstration considers the isobaric thermodynamic process of compressing or expanding an ideal gas. Assume that a constant external pressure acts on the piston containing the gas. As you vary the external pressure, the horizontal line in the graph changes accordingly. When the variables for the initial and final volumes are changed, the position of the gridlines on the graph and the initial and final position of the head of the piston move. Work is calculated in the Demonstration with the convention used in chemistry: when the ideal gas expands, the work done is negative (i.e. the ideal gas "loses" energy), and vice versa.

This Demonstration looks at a time-dependent superposition of quantum particle-in-a-box eigenstates. The upper panel shows the complex wavefunction, where the shape is its modulus and the coloring is according to its argument (the range 0 to 2π corresponds to colors from red to magenta). The lower panel shows the eigenenergies in blue and the energy of the superposition state in red.

This Demonstration treats the quantum-mechanical problems of a particle in a box. We consider both the one-dimensional and three-dimensional cases.

This Demonstration shows both the qualitative and quantitative behavior of phase changes in water

This Demonstration shows how these nucleation conditions can be altered by varying the parameters of temperature and composition in crystalline media.

A Stirling engine takes advantage of the thermodynamic properties of compression and expansion of gases to produce work. This Demonstration tracks the changes in pressure (atm) and volume (L) of the working fluid during a reversible Stirling cycle

This demonstration shows relative humidity and how it affects our daily lives, particularly what it does to our hair.

Effect of Temperature on Partial Miscibility in a Binary-Liquid System This Demonstration shows how the mole fraction of a binary liquid system, composed of two partially miscible liquids, changes with temperature.

This Demonstration shows the theory proposed by R. A. Marcus in 1956 [1–3] which provides a method to calculate the activation energy of a reaction by using a parabolic model to calculate activation energy.

This Demonstration shows the effects of changes in altitude on alveolar oxygen pressure using the alveolar gas equation.

This Demonstration considers the variation of heat capacity of an ideal diatomic gas, specifically hydrogen, with temperature.

This Demonstration shows the heating or cooling effects achieved by salt packs.

This Demonstration shows Liquid miscibility, which is the measure of how well a pair of liquids mixes/dissolves

This Demonstration shows carbon dioxide sublimation from dry ice is a well-known phenomenon, which occurs at standard temperature and pressure.

This Demonstration shows how the rate of evaporation of water from a flat surface changes with temperature, wind speed, drying time, solar irradiance, air pressure and relative humidity.

This Demonstration considers the rate of dissolution of three drugs in everyday use, modeled by a tablet dissolving in a beaker of water.

This Demonstration manipulates the initial temperature and mass of a sample of liquid to calculate the maximum quantity of heat it can transfer when its temperature changes.

This Demonstration shows the effect of radius on the band gap energy of CdSe in quantum dots that emit in the visible light range under excitation with UV.

This Demonstration shows the diffusion of two gases from opposite ends of a tube.

This Demonstration examines the rates of respiration as a function of cell type and temperature, displaying an animation of the cell with oxygen input and water output from mitochondria.

This Demonstration considers the solubility of two different gases, CO_{2} and O_{2}, in water.

This Demonstration shows the rate of diffusion in an alveolus using Fick's law.

This Demonstration manipulates the number of moles of CO_{2} and the temperature to visualize the equilibria of sublimation of solid CO_{2} and the dissolution of gaseous CO_{2} into aqueous solution.

This Demonstration shows the diffusion of oxygen molecules across a membrane (represented by a box) according to Fick’s law.

This Demonstration displays the rate at which the gas molecules of carbon dioxide and oxygen diffuse through the alveolar wall as a function of alveolar thickness.

This Demonstration shows the quantum effects observed on a single electron trapped in a spherical nanoparticle, modeled as a particle in a sphere.

This Demonstration shows the equilibration between two objects (a human and a chair) at different temperatures in thermal contact with one another.

This Demonstration illustrates the heat transfer between two vessels containing water, in thermal contact with one another.

- Coulomb's Law for Three Point Charges
- Compressibility Factors for van der Waals Gases
- Isobaric Compression and Expansion of an Ideal Gas
- Work Done in Reversible and Irreversible Compression of an Ideal Gas
- Adiabatic Expansion and Compression of an Ideal Gas
- Reversible and Irreversible Isothermal Expansion of an Ideal Gas
- Time-Dependent Superposition of Harmonic Oscillator Eigenstates
- Boundary Conditions for a Semi-Infinite Potential Well
- Fourier Transform Pairs

- Bound States of a Finite Potential Well
- Complex Spherical Harmonics
- Bound States of a Semi-Infinite Potential Well
- Time-Dependent Superposition of Particle-in-a-Box Eigenstates
- Integrals over Dirac Delta Function Representations
- Orthonormality of Standing Waves
- A Complex Gaussian Function
- Superposition of Standing Waves
- Classical Barrier Crossing and Phase Space
- Hydrogen Atom Radial Functions
- Time-Dependent Superposition of Rigid Rotor Eigenstates
- Rotational-Vibrational Spectrum of a Diatomic Molecule

- Temperature-Dependent Rotational Energy Spectrum
- Variational Principle for Quantum Particle in a Box
- Time-Dependent Superposition of 2D Particle-in-a-Box Eigenstates
- Time Evolution of a Quantum Free Particle in 2D
- Time Evolution of a Quantum Free Particle in 1D
- Superposition of Quantum Harmonic Oscillator Eigenstates: Expectation Values and Uncertainties
- Probability Densities, Expectation Values, and Uncertainties for Gaussian Wavepackets
- Classical Motion and Phase Space for a Morse Oscillator
- Classical Motion and Phase Space for a Harmonic Oscillator
- Perturbation Theory Applied to the Quantum Harmonic Oscillator