Advanced Manufacturing

Ideal Gas Law

Ideal Gas Law

listen to this story
An ideal gas is defined as one in which all collisions between atoms or molecules are perfectly elastic and in which there are no intermolecular attractive forces.
Ideal gas law is a generalization containing both Boyle’s law and Charles’s law as special cases and states that:
In such a gas, all the internal energy is in the form of kinetic energy and any change in internal energy is accompanied by a change in temperature. An ideal gas can be characterized by three state variables:
  • absolute pressure (P),
  • volume (V),
  • and absolute temperature (T).
The relationship between them may be deduced from kinetic theory and is called the Ideal gas law.
PV = kT = nRT
where
  • n is the total number of moles,
  • NA = Avogadro’s Number = 6.02217 · 1023 molecules/mole,
  • R = Universal gas constant = 8.314 J/K · mol ,
  • k = Boltzmann Constant = R/NA = 1.380622 · 10-23 J/K.
The ideal gas law can be viewed as arising from the kinetic pressure of gas molecules colliding with the walls of a container in accordance with Newton’s laws. But there is also a statistical element in the determination of the average kinetic energy of those molecules. The temperature is taken to be proportional to this average kinetic energy; this invokes the idea of kinetic temperature.