13.1 and 14 Flashcards
2 extra points about kinetic theory of gases
random walk
no repulsive or attractive forces
3 assumptions in kinetic theory of gases
the particles in a gas are considered to be small, hard spheres with an insignificant volume
the motion of the particles in a gas is rapid, constant, and random
all collisions between particles in a gas are perfectly elastic
3 units of pressure
pascal
atm - standard atmosphere
millimeters of Hg - mm Hg
which unit of pressure is SI
kPa
what causes pressure
simultaneous collisions of billions of rapidly moving particles in a gas with an object
What is STP
standard temperature and pressure
0 degrees C
101.3 kPa
1 atm
What is the volume of 1 mole of gas at STP
22.4 L
what is the relationship between temperature and average kinetic energy
directly proportional
what does it mean when two variables are directly proportional
increase or decrease together
what does it mean when two variables are inversely proportional
1 increases while the other decreases
why does pressure increase when you increase the number of moles
adding moles increases the number of collisions which results in pressure
why does pressure increase when you increase the temperature
the kinetic energy increases and faster-moving particles strike the walls of their container with more energy
why does air rush out of an object at high pressure and into an object at low pressure
differential pressure
the air is trying to reach atmospheric pressure
what is the combined gas law
P1V1 P2V2
—– = ——
T1 T2
what variable can be calculated from the ideal gas law that cannot be calculated by the combined gas law
number of moles
What is the ideal gas law
N=PV
—
RT
PV=nRT
what is r
ideal gas constant
8.31
how to determine R at stp
R*moles
what is partial pressure
the contribution each gas in a mixture makes to the total pressure
what is compressibility
a measure of how much the volume of matter decreases under pressure
what is effusion
a gas escapes through a tiny hole in its container
what is diffusion
the tendency of molecules to move toward areas of lower concentration until the concentration is uniform
what is the total pressure
the sum of the partial pressures
diffusion and effusion rates
gases of lower molar mass do it faster than those with high molar masses
the rate of effusion of a gas is _____ compared to a gas’s molar mass
inversely proportional to the square root of a gas’s molar mass
when are real gases most similar to ideal gases
high temperatures and low pressures
as pressure increases volume…
decreases
as temperature increases volume…
increases
as temperature increases, pressure…
increases
why are gases compressible
volume of particles is smaller than volume of gas
distance between particles is large
what is kinetic energy
the energy an object has because it is moving
what is a vacuum
empty space with no particles and no pressure
