Gas Law Lab
Make a prediction. Move the piston. See the science.
Each dot represents a share of the gas. Dot sizes, speeds and cylinder dimensions are illustrative, not to scale.
View graph values as a table
Curve calculated from PV = nRT under the fixed conditions above. The graph shows equilibrium states; piston motion is not a time-resolved thermodynamics experiment.
Ideal gas calculator
Choose the unknown. Enter the other three quantities in your preferred units.
P = nRT / V
Use kelvin inside the equation. Celsius inputs are converted using K = °C + 273.15. Pressure is absolute pressure, not gauge pressure.
R = 8.314 kPa dm³ mol⁻¹ K⁻¹. Calculations retain precision internally and display up to four significant figures.
The science behind the model
The ideal gas equation is PV = nRT. It assumes particles have negligible volume, negligible attractions and elastic collisions. Real gases tend to behave more ideally at lower pressures and higher temperatures, away from condensation.
The piston represents a sequence of equilibrium states. Compression is isothermal in the Boyle experiment: energy is exchanged with the surroundings to keep temperature fixed. The heating-at-fixed-volume experiment locks the piston. For Charles and Avogadro investigations, the external pressure is held constant and the piston can move.
Pressure results from momentum transferred to walls. Particle speed in this illustration scales with the square root of kelvin temperature; average kinetic energy is proportional to kelvin temperature. All dots have the same model mass. The animation is a two-dimensional illustration with a limited number of representative dots, not a molecular-dynamics calculation or a measured collision-rate graph.
The displayed pressure and graph come from the gas equation, not from counting animation collisions. Particle number represents amount; particle size does not change. Pause and reduced-motion mode freeze movement without changing the science.
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