PV=nRT approximates gases at low pressure and high temperature.
PV=mRT=nR_uT with R=R_u/M. Valid at low pressure and high temperature relative to critical values. P and T must be absolute. Combined gas law P₁V₁/T₁=P₂V₂/T₂. Real-gas deviations are given by Z or equations of state (van der Waals, Peng-Robinson).
1 kg of air at 300 K and 100 kPa occupies 0.861 m³.
The ideal gas law gives a fast estimate of gas behaviour, so it is used for air, combustion products and many engineering calculations.
PV=nRT approximates gases at low pressure and high temperature.
The ideal gas law gives a fast estimate of gas behaviour, so it is used for air, combustion products and many engineering calculations.
At low pressure and high temperature, relative to the gas's critical point, where molecular forces and volume are small.
About 287 joules per kilogram per kelvin, which is the specific gas constant, while R bar is the universal gas constant.
Typical applications include estimating the density of air in a duct at a given temperature and pressure, calculating the amount of gas in a cylinder at a set state and checking whether a gas can be treated as ideal in a compressor.
Study "First law of thermodynamics" first (topic 10 of 105 in Thermodynamics & Fluids). It covers the groundwork this topic builds on.
R_u=8.314 kJ/kmol·K. R_air=0.287 kJ/kg·K. Molar volume 22.4 L at STP.
1 kg of air at 300 K and 100 kPa occupies 0.861 m³.
The next topic is "Thermodynamic processes", which builds directly on this one.
It is classed as Beginner in Thermodynamics & Fluids (topic 11 of 105). It is an entry-level topic. It relies only on basic school mathematics and the ideas introduced earlier in this discipline.
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