Ideal & Real Gases

Ideal & Real Gases

·  The gas laws quantify the relationship between temperature, pressure, volume and number of mole for an ideal gas

·  An ideal gas is one that obeys ALL the proposals of the kinetic molecular theory

·  Unfortunately, not all gases obey all the proposals in the kinetic molecular theory, particularly that NO FORCES EXIST BETWEEN PARTICLES

·  Real gases are closest to ideal gases at high temperature and low pressure as this is when gas particles are furthest apart and forces between them are negligible

·  Some gases are more “ideal” than others e.g. helium compared to ammonia (due to intermolecular forces and molecular size).

·  Boyle’s Law or

·  Charle’s Law or

·  If the volume of a gas is measured at different temperatures and graphed

Extrapolation of this graph will show V= 0 at T = -273˙C. This temperature is sometimes called absolute 0 because at this point, gas particles have no kinetic energy and stop moving.