Boyle-Mariotte Law

BOYLE-MARIOTTE LAW (Boyle-Mariotte), states that the product of the volume of a given mass of gas and its pressure is a constant quantity. The law was discovered in 1662 by the English physicist Boyle and was again found only in 1676 by the French physicist Mariotte (it is not known to what extent the works of Mariotte were independent). The law is valid (strictly speaking) for so-called ideal gases, the molecules of which do not possess finite dimensions and do not interact with each other at all. At ordinary temperatures and pressures, such ideal gas properties are possessed by: H, helium, etc. On the contrary, CO₂ begins to show deviations from the Boyle-Mariotte law already at not too high pressures and not too low temperatures. Deviations from the Boyle-Mariotte law were first noted by the French physicist Regnault. But only Van der Waals found the relationship between volume and pressure, which applies to gases differing from ideal in their properties (see Van der Waals' law).