softmatter:Ideal Gas
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An ideal gas is a hypothetical gas consisting of particles of zero volume that experience no intermolecular forces, but undergo elastic collisions with the walls.
Ideal Gas Law
Thermodynamic treatment
Formulated by Clapeyron, the ideal gas law can be expressed as:
- PV = nRT
where, P is pressure, V is volume, n is the amount of material (mol or lb-mol), R is the gas constant and T is the temperature. For various units, R has the value of:
| Gas constant R | (Units) |
|---|---|
| 8.314472 | meter3·Pascal·Kelvin-1·mol-1 |
| 0.08205784 | Liter·atm·Kelvin-1·mol-1 |
| 62.3637 | Liters·mmHg·Kelvin-1·mol-1 |
| 10.7316 | ft3·psi·°Rankin-1·lb-mol-1 |
Statistical Mechanics treatment
Additionally, the gas law can be expressed in terms of the number of atoms/molecules:
- PV = NkT
where P, V, and T are unchanged, but now N corresponds to the number of atoms/molcules, and k is the Boltzmann constant. The Boltzmann constant has the following values for various units:
| Boltzmann constant k | (Units) |
|---|---|
| 1.380 6504x10-23 | Joules/Kelvin |
| 8.617 343x10-5 | electron-volt/Kelvin |
| 1.3807x10-16 | erg/Kelvin |
