A Level Physics Practice Test: Ideal Gas — Flashcards

An ideal gas is a hypothetical gas made up of randomly moving particles that don't interact with each other. The ideal gas concept is useful because it follows the ideal gas law, a simplified equation of state.

Here are some characteristics of ideal gases:
All collisions between molecules are perfectly elastic
There are no intermolecular attractive forces
The volume of molecules and forces between the molecules are so small that they have no effect on the behavior of the gas
Ideal gas molecules do not attract or repel each other
The only interaction between ideal gas molecules would be an elastic collision upon impact with each other or an elastic collision with the walls of the container 

Ideal gases can be described by three variables: Absolute pressure (P), Volume (V), and Absolute temperature (T). 
The ideal gas equation of state is: PV = MRT and P/ρ = MRT. 
Although there is no ideal gas, all real gas tends to approach that property when the density gets low enough. This is possible because the molecules of the gas are so far apart from one another that they do not interact with each other. 

The Ideal Gas Law states that in an adiabatic process in which the temperature remains constant, any change in the volume will result in a change in the pressure, or P1V1 = P2V2 (Boyle's Law). 
The Ideal Gas Law is only accurate at relatively low pressures and high temperatures. To account for deviation from the ideal situation, a correction factor called the Gas Compressibility Factor, or Z-factor, is included.