unit 7 Flashcards
kinetic molecular theory (kmt)
describes the behavior of matter in terms of particles in potion, it makes assumptions about the size, motion, and energy of gas particles
kmt - particle size and attractive forces
small particles, little to no attraction
kmt - particle motion
constant and random motion in a straight line
kinetic energy of a particle
1/2 mv^2
how does kmt explain gas expanding or contracting
when the volume of a container increases, particles fill that space
diffusion
the movement of one material through another
kmt diffusion
particles can easily flow because there is no attraction
effusion
diffusion through a tiny opening
what effuses faster
lighter gasses effuse faster
grahams law of effusion
rate of effusion is inversely proportional to the square root of its molar mass
pressure
when particles collide with the walls of their containers
used to measure atmospheric pressure
barometer
used to measure pressure of a gas
manometer
ideal gas
a gas where its particles take up no space
ideal gas properties
-no imf attraction forces
-not attracted to or repelled by the walls of the container
-constant random motion in straight lines
-perfectly elastic
-follows gas laws
when do real gasses act most like ideal gasses
at high temps and low pressures
what types of gas particles deviate most from ideal gas behavior
large gas particles
intramolecular forces
forces inside a molecule
intermolecular forces
forces between molecules
solid to liquid
melting, energy and distance up, imfs down
liquid to solid
freezing, energy and distance down, imfs up
liquid to gas
boiling / vaporation, energy and distance up, imfs down
gas to liquid
condensation, energy and distance down, imfs up
solid to gas
sublimation, energy and distance up, imfs down
gas to solid
deposition, energy and distance down, imfs up
volatile liquids
evaporate easy, low imfs - gasoline, perfume - high pressure
non volatile liquids
do not evaporate easy, high imfs - water - strong imfs have a lower equilibrium vapor pressure because when imfs are strong its difficult for molecules to enter a gas phase, so there are fewer molecules of gas and less pressure
relationship of imfs and pressure
imfs are strong so it is difficult for it to enter gas phase and so there are fewer molecules of gas which is a lower pressure
boiling point and pressure
lower the atmospheric pressure, lower the boiling point
critical point
the temperature above which gas cannot be liquified no matter the pressure
triple point
condition where all three phases can be present
boyles law
p and v are inversely proportional
charles law
v and t are directly proportional
gay-lussacs law
p and t are directly proportional
equilibrium
a dynamic condition in which opposing changes are occurring at the same rate in a closed system
equilibrium vapor pressure of a liquid
the pressure exerted by a vapor in equilibrium with its corresponding liquid at a given temperature,,, pressure of a gas above its liquid
increase in temperature ___ equilibrium pressure,, why?
increases, because increasing temp increases KE and so more molecules change from liquid to gas, so there are more molecules which means more pressure
boiling or evaporation
boiling happens within the liquid while evaporation is just at the surface
boiling point
the temperature where the equilibrium vapor pressure equals the surrounding atmospheric pressure
what happens to temp when a liquid boils
it stays constant
volatile is __ vapor pressure
high vapor pressure == volatile
why does increasing atmospheric pressure increase boiling point
more energy is required to boil
how can gas pressure be increased
decrease volume, increase temperature, increase amt of gas
