Compute pressure, volume, temperature and moles using PV=nRT and combined gas law.
A gas laws calculator handles the ideal gas equation (PV = nRT), Boyle's law (constant T), Charles's law (constant P), Gay-Lussac's law (constant V), and the combined gas law. These describe the behaviour of gases under different conditions of pressure, volume, temperature, and moles.
The ideal gas law is highly accurate for most gases at normal temperatures and pressures (less than a few atmospheres, well above the condensation point). Significant deviation appears near the critical point or under high pressure — described by the Van der Waals equation as a refinement.
PV = nRT
Inputs: 2 mol of an ideal gas at 25 °C in a 10 L container
The ideal gas law assumes pressure is proportional to absolute temperature (number of molecular collisions per unit area). At Celsius zero (273.15 K) gas pressure is not zero — gas only ceases entirely at absolute zero (0 K). Using Celsius in PV = nRT gives nonsensical predictions for cold gases. Always convert: T(K) = T(°C) + 273.15.
High pressure (gas molecules occupy a significant fraction of total volume — neglected in the ideal law). Low temperature (close to condensation, where intermolecular forces matter). High molar mass (large molecules with stronger interactions). For everyday conditions — room temperature, ≤ 5 atm — the ideal gas law is accurate to within 1–2% for most gases.
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