This form submits information to an interactive model which calculates compressibility and pressure based on several factors. Graphs will be generated for several different temperatures, each graph showing the pressure and compressibility over a range of volumes. Input the temperatures separated by a space or comma at which you want to calculate these graphs. Up to 10 temperatures may be entered. These temperatures are proportions of the critical temperature, which is a factor in the compressibility. The critical temperature depends on the gas, but is usually low. At critical temperature, pressure, and volume, the gas changes phase.

Compressibility expresses how much a gas is behaving like an ideal gas under any conditions. If the compressibility equals one, then the gas is behaving exactly like an ideal gas. If the compressibility deviates much from one, then the ideal gas equation will not accurately model the real gas under those conditions. This script uses the Beattie-Bridgeman equation to calculate the behavior of the gas, even when not acting ideally.

Developed by

Shodor
in cooperation with the Department of Chemistry,
The University of North Carolina at Chapel Hill