Thermodynamics
Ideal gas sandbox
Change n, V and T and watch P follow PV = nRT.
Ideal gas sandbox — interactive Thermodynamics simulation. Change n, V and T and watch P follow PV = nRT. Free browser-based virtual physics lab with live SI measurements and a guided tutorial.
Ideal gas law
Change n, V and T and watch P follow PV = nRT.
The ideal gas law combines Boyle's, Charles's, and Avogadro's laws into one state equation. This sandbox keeps temperature explicit so you can see pressure rise when volume shrinks or moles increase. Molecular collisions against the piston wall produce the macroscopic pressure readout.
- PV = nRT
- KE_avg ∝ T
Investigation brief
Plan the question before you open the lab
The brief mirrors the prerendered page: driving question, competing predictions, variable roles, governing laws, setup, analysis and extension prompts remain visible and in this order.
Driving question
A fixed amount of gas is sealed in a rigid container. If you heat it up, what happens to its pressure?
Predictions to weigh
- Pressure decreases as temperature rises.
- Pressure increases proportionally with temperature.
- Pressure doesn't depend on temperature.
Variable roles
What you set:
- Temperature T (K)
What you measure:
- Internal energy U (J)
- Pressure P (kPa)
How the investigation runs
- Open the ideal-gas-sandbox preset and press Reset. 1 mol of argon fills a fixed volume of 0.0249 m³.
- Enable the pressure readout on the chamber.
- Set the gas temperature for each trial and record the pressure.
Governing equation
Ideal Gas Law — P = n·R·T / V
For n moles of ideal gas, pressure, volume, and temperature are locked together by P·V = n·R·T. At fixed n and V, pressure rises in direct proportion to absolute temperature.
Internal Energy of an Ideal Gas — U = f/2·n·R·T
An ideal gas's internal energy depends only on its temperature (and degrees of freedom f), not on pressure or volume separately: U = (f/2)nRT.
What the printable worksheet asks students to work out
- For one trial, compute P = nRT/V using n = 1 mol, R = 8.314 J/(mol·K), V = 0.0249 m³. Compare to the table.
- Explain why, at fixed volume and amount of gas, pressure and absolute temperature are directly proportional.
Where this shows up beyond the lab
- The ideal gas law requires temperature in kelvin, not Celsius. Explain why using Celsius (which allows negative and zero values) would break the direct proportionality you found.
- Your internal-energy column also grows with temperature, at fixed volume. Explain, using U = (f/2)nRT, why heating a fixed amount of gas at constant volume increases both its pressure and its internal energy together.
- AP Physics 2 — Unit 9: Thermodynamics
- IB Physics — B.3 Gas laws
- General High School Physics — Heat, temperature & gas laws
- NGSS High School Physics — Thermal energy transfer
- Up or down?
- Raise the temperature
- Capture the pressure
- Open the data
- Explain your evidence
Open the interactive simulation to build the scene, press Play, and explore with live measurements and a guided tutorial.