Chapter 9 Gases
Chapter 9 Key Terms
temperature at which the volume of a gas would be zero according to Charles’s law.
(also, Gay-Lussac’s law) pressure of a given number of moles of gas is directly proportional to its kelvin temperature when the volume is held constant
unit of pressure; 1 atm = 101,325 Pa
volume of a gas at constant temperature and pressure is proportional to the number of gas molecules
(bar or b) unit of pressure; 1 bar = 100,000 Pa
device used to measure atmospheric pressure
volume of a given number of moles of gas held at constant temperature is inversely proportional to the pressure under which it is measured
volume of a given number of moles of gas is directly proportional to its kelvin temperature when the pressure is held constant
ratio of the experimentally measured molar volume for a gas to its molar volume as computed from the ideal gas equation
Dalton’s law of partial pressures
total pressure of a mixture of ideal gases is equal to the sum of the partial pressures of the component gases
movement of an atom or molecule from a region of relatively high concentration to one of relatively low concentration (discussed in this chapter with regard to gaseous species, but applicable to species in any phase)
transfer of gaseous atoms or molecules from a container to a vacuum through very small openings
rates of diffusion and effusion of gases are inversely proportional to the square roots of their molecular masses
pressure exerted by a fluid due to gravity
hypothetical gas whose physical properties are perfectly described by the gas laws
constant derived from the ideal gas equation R = 0.08206 L atm mol–1 K–1 or 8.314 L kPa mol–1 K–1
relation between the pressure, volume, amount, and temperature of a gas under conditions derived by combination of the simple gas laws
theory based on simple principles and assumptions that effectively explains ideal gas behavior
device used to measure the pressure of a gas trapped in a container
average distance a molecule travels between collisions
concentration unit defined as the ratio of the molar amount of a mixture component to the total number of moles of all mixture components
pressure exerted by an individual gas in a mixture
SI unit of pressure; 1 Pa = 1 N/m2
unit of pressure common in the US
force exerted per unit area
amount of gas diffusing through a given area over a given time
measure of average speed for a group of particles calculated as the square root of the average squared speed
standard conditions of temperature and pressure (STP)
273.15 K (0°C) and 1 atm (101.325 kPa)
volume of 1 mole of gas at STP, approximately 22.4 L for gases behaving ideally
unit of pressure; 1 torr = 1/760 atm
modified version of the ideal gas equation containing additional terms to account for non-ideal gas behavior
pressure exerted by water vapor in equilibrium with liquid water in a closed container at a specific temperature