Chapter 5 Flashcards
pressure
The force exerted per unit of surface area
barometer
A device used to measure atmospheric pressure. Most commonly, a tube open at one end, which is filled with mercury and inverted into a dish of mercury
pascal
The SI unit of pressure; 1Pa=1N/m^2
standard atmosphere
The average atmosphere pressure measured at sea level and 0C, defined as 1.01325x10^5 Pa
millimeter of mercury(torr)
A unit of pressure based on the difference in the heights of mercury in a barometer or manometer.
torr
A unit of pressure identical to 1 mmHg
ideal gas
A hypothetical gas that exhibits linear relationships among volume, pressure, temperature, and amount (mol) at all conditions; approximated by simple gases at ordinary conditions.
boyle’s law
The gas law stating that, at constant temperature and amount of gas, the volume occupied by a gas is inversely proportional to the applied (external) pressure.
charles’s law
The gas law stating that at constant pressure, the volume occupied by a fixed amount of gas is directly proportional to its absolute temperature
Avogadro’s law
The gas law stating that, at fixed temperature and pressure, equal volumes of any ideal gas contain equal numbers of particles, and , therefore, the volume of a gas is directly proportional to its amount
standard temperature and pressure
The reference conditions for a gas
standard molar volume
The volume of 1 mol of an ideal gas at standard temperature and pressure: 22.4141L
ideal gas law
An equation that expresses the relationships among volume, pressure, temperature, and amount (mol) of an ideal gas: PV=nRT
universal gas constant
A proportionality constant that relates the energy, amount of substance, and temperature of a system
partial pressure
The portion of the total pressure contributed by a gas in a mixture of gases
Dalton’s law of partial pressures
A gas law stating that, in a mixture of unreacting gases, the total pressure is the sum of the partial pressures of the individual gases
mole fraction
A concentration term expressed as the ratio of moles of one component of a mixture to the total moles present
kinetic-molecular theory
the model that explains gas behavior in terms of particles in random motion whose volumes and interactions are negligible
rms speed
The speed of a molecule having the average kinetic energy; very close to the most probable speed
effusion
The process by which a gas escapes from its container through a tiny hole into an evacuated space
Graham’s law of effusion
A gas law stating that the rate of effusion of a gas inversely proportional to the square root of its density
diffusion
the movement of one fluid through another
van der Waals equation
an equation that accounts for the behavior of real gasses
van der Waals constants
Experimentally determined positive numbers used in the van der Waals equation to account for the intermolecular attractions and molecular volume of real gasses
