How to use it
Select the unknown. Enter the other three positive physical quantities. Select units; the unknown field is ignored. Temperature must be above absolute zero.
Method and worked example
PV = nRT with R = 8.31446261815324 Pa·m³·mol⁻¹·K⁻¹. Pressure is converted to pascals, volume to cubic meters, and Celsius to kelvin before solving. One atmosphere equals 101325 Pa; one mmHg is modeled as 101325/760 Pa.
Example
At 1 atm and 273.15 K, one mole of ideal gas occupies approximately 22.414 L.
Assumptions and limitations
The ideal-gas model is an approximation and can be inaccurate at high pressure, low temperature, or near phase transitions. This is not engineering design, pressure-vessel, or laboratory safety guidance.
Privacy and accessibility
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