## Gas Laws Glossary

 Gas the form of matter that is an easily compressible fluid; a given quantity of gas will fit into a container of any size and shape Standard temperature and pressure (STP) the reference conditions for gases. chosen by convention to be 00C and 1 atm Absolute temperature scale a temperature scale in which the lowest temperature that can be attained theoretically is zero Atmosphere (atm) a unit of pressure equal to exactly 760 mmHg; 1 atm = 101.325 kPa Boyle's law a law stating that the volume of a sample of gas at a given temperature varies inversely with the applied pressure Charies's law a law stating that the volume occupied by any sample of gas at a constant pressure is directly proportional to the absolute temperature Density the mass per unit volume of a substance or solution. Diffusion the process whereby a gas spreads out through another gas to occupy the space with uniform partial pressure Effusion the process in which a gas flows through a small hole in a container Ideal gas law the equation PV = nRT, which combines all of the gas laws Kelvin (K) the SI base unit of temperature; a unit on an absolute temperature scale Kinetic-molecular theory the theory that a gas consists of molecules in constant random motion Partial pressure the pressure exerted by a particular gas in a mixture Pressure the force exerted per unit area of surface Vapor the gaseous state of any kind of matter that normally exists as a liquid or solid.