AP Chem - Chapter 5 - Gases Flashcards
does a gas uniformly fill any container
yes
are gases easily compressed
yes
will gases mix completely with any other gas
yes
do gases exert pressure on their surroundings
yes
what is a barometer
a device used to measure atmospheric pressure
how does a barometer work
a glass tube is filled with mercury and inverted in a dish of mercury. mercury flows out of the tube until the pressure of the column of mercury is equal to the pressure of the air
what affects atmospheric pressure
weather conditions
altitude
what is Boyle’s law
PV = k
pressure and volume are inversely proportional
what is charles law
V = bT
temperature and volume are directly proportional
why do gas law probs have to be in Kelvin
so its a direct relationship since kelvin is an absolute temperature scale
what is avogadro’s law
v =an
volume and number of moles are directly proportional
what is the ideal gads law
PV = nRT
when do gases behave closet to the ideal gas law
low pressures and high temps
what is the combined gas law
PV/nT = PV/nT
what is dalton’s law of partial pressures
for a mixture of gases in a container, the total pressure exerted is the sum of the pressures that each gas would exert if it were alone
Ptotal = P1 + P2 + P3 …
what does the partial pressure of each gas in a mixture of gases in a container depend on
the number of moles of that gas, not the identity or composition of the involved particles
what does the fact that the pressure exerted by an ideal gas is not affected by the identity of the gas particles reveal about ideal gases
1) the volume of the individual gas particles must not be important
2) the forces among the particles must not be important
what are the 4 parts of kinetic molecular theory
1) the volume of the individual particles in a gas can be assumed to be negligible bc the particles are so small compared with the distances between them
2) the particles are in constant motion
3) the particles are assumed to exert no forces on each other
4) avg KE is assumed to be directly proportional to the kelvin temp of the gas
what is the kinetic molecular theory
a simple model that attempts to explain the properties of an ideal gas
what is the relationship between avg KE and kelvin temp
directly proportional
what is diffusion
the mixing of gasses
what is the rate of diffusion
the rate of the mixing gases
what is effusion
the passage of a gas through a tiny orifice into an evacuated chamber
what does the rate of effusion measure
the speed at which the gas is transferred into the chamber
what is graham’s law of effusion
the rate of effusion of a gas is inversely proportional to the square root of the mass of its particles
what does the effusion rate for a gas depend directly on
the average velocity of its particles
when do gases come close to following the ideal gas law
low pressures and/or high temps
in what ways did van der waals modify the ideal gas law
corrected it for the finite volume of the particles
corrected it for the attractions that occur among the particles
When a sample of oxygen gas in a closed container of constant volume is heated until it’s absolute temperature is doubled, what else doubles?
The pressure of the gas
When a sample of oxygen gas in a closed container of constant volume is heated until it’s absolute temperature is doubled, what else doubles?
The pressure of the gas
