Ideal Gas Law Calculator
PV = nRT ties four quantities together so that fixing any three fixes the fourth. That makes it the ideal shape for a self-checking calculator: whichever variable you solve for, substituting the answer back must make both sides equal. This generates a gas problem, solves it, and prints both sides so the equality is visible rather than promised.
What this generator does
Builds a physically sensible gas state, hides one of the four quantities, and solves for it using the ideal gas law. It then reports pressure times volume alongside moles times the gas constant times temperature, which must come to the same number.
How to use this tool
- Choose which quantity to solve for and generate a scenario.
- Read the answer, then check that PV and nRT come to the same number.
- Note that temperature is in kelvin — using Celsius is the classic mistake.
- Try the same scenario solving for a different variable.
Understanding the controls
- Solve for
- Which of the four quantities to treat as unknown. The other three are given, and the answer is checked by substitution whichever you pick.
- Seed
- Any word reproduces exactly the same scenario, so a problem can be set and marked later.
Common use cases
- Chemistry and physics practice with answers that check themselves
- Generating gas-law problems for a lesson or homework
- Showing why absolute temperature is not optional
- Sanity-checking a calculation done by hand
- Setting the same problem twice from a seed
How this generator works
Substituting the answer back is the entire check, and it is a genuinely strong one: an error in the rearrangement would make the two sides disagree immediately. Values are chosen to be physically sensible — a few moles, a fraction of a cubic metre, a temperature between 200 and 600 kelvin — so the numbers resemble something you might actually meet.
Randomness and fairness
The scenario is drawn at random within sensible physical ranges; solving for the unknown is then deterministic. A seed reproduces the same problem exactly and is therefore explicitly not cryptographically secure. Without a seed the browser's cryptographically secure generator is used.
For how randomness is produced across the whole site, see how Generate Random works.
Limitations and good to know
- The ideal gas law is an approximation. Real gases depart from it at high pressure and near condensation, where molecular volume and attraction stop being negligible.
- SI units throughout — pascals, cubic metres, moles and kelvin. Litres and atmospheres need converting first.
- One state at a time; the combined gas law relating two states is not covered here.
- No gas mixtures or partial pressures.
- A scenario is not retained, so copy it before closing the tab.
Privacy and your data
The scenario and its solution are computed on your own device. Neither the figures nor your seed leave the browser.
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