Key Terms
Barometer - a device that measures atmospheric pressure with a glass tube inverted in a dish of mercury
Manometer - an instrument used for comparing the relative pressures of a gas and the atmosphere
mmHg - a unit of pressure derived from the observed change in a column of mercury
Torr - named after the Italian scientist Evangelista Torricelli, it is a unit of pressure equivalent to mmHg.
Standard atmosphere (atm) - a unit of pressure equivalent to 760 mmHg or 101 324 Pa.
Pascal (Pa) - the SI unit of pressure, it is equivalent to one newton per meter squared.
Boyle's Law - states that pressure and volume are inversely related at constant temperature
Ideal Gas - a gas that strictly obeys Boyle's Law
Charles's Law - states that temperature and volume are directly related at constant pressure
Absolute Zero - the coldest possible temperature, equivalent to 0 K
Avogadro's Law - states that the volume of a gas is proportional to the number of moles of particles
Universal gas constant - equivalent to 0.0821 L x atm / K x mol, represented by R
Ideal Gas Law - PV = nRT
Molar volume - the volume taken up by an ideal gas at STP, equivalent to 22.4 L
Standard Temperature and Pressure - abbreviated STP, represents conditions at 0oC and 1 atm.
Dalton's Law of Partial Pressure - states that the total pressure of a sample of gas is equivalent to the partial pressure of the component gases
Partial Pressures - the pressure that a particular gas would exert alone in a container.
Mole fraction - the ratio of the number of moles of a given compound to the total moles.
Kinetic Molecular Theory (KMT) - a model that attempts to explain the properties of an ideal gas
Root mean square velocity - the average velocity of gas particles
Diffusion - the mixing of gases, the movement of a compound from higher concentration to areas of lower concentration
Effusion - the passage of gas through a small hole into an evacuated chamber
Graham's Law of Effusion - sq. rt (M1) / sq. rt (M2) = rate of effusion of gas 2 / rate of effusion for gas 1
van der Waals equation - [Pobs + a(n/V)^2](V - nb) = nRT, the real gas law.
Atmosphere - the dome of gases that surrounds the Earth
Air pollution - the clouding of the air by pollutants and human activity
Photochemical Smog - when light is required to initiate some reactions