gas laws Flashcards
boyle’s law equation?
P1V1 = P2V2
what does boyle’s law state? which variables held constant?
pressure and volume are inversely proportional when temperature and amount of gas (mol) are held constant.
charles’ law equation?
V1/T1 = V2/T2
what does charles’ law state? what variables are held constant?
the volume of gas is directly proportional to temperature when the pressure and amount of gas (mol) are held constant.
what is gay-lussac’s equation?
P1/T1 = P2/T2
what does gay-lussac’s law state? what variables are held constant?
temperature and pressure are directly proportional when volume and moles of gas are held constant.
what is the combined gas law equation? which 3 variables does it “combine”?
P1V1/T1 = P2V2/T2
temperature, volume, and pressure
when do you use the combined gas law?
- when there’s an initial and final scenario
- when 2 variables are changing simultaneously
what is avogadro’s law equation?
V1/n1 = V2/n2
what does avogadro’s law state? which variables are held constant?
volume and the amount of moles of gas are directly proportional when the temperature and pressure are held constant.
what is dalton’s law of partial pressures equations? (one to find partial pressure, one to find the total pressure)
Ptotal = P1 + P2 + P3 +….
Partial pressure = X * Ptotal (mole fraction of given gas multiplied by total pressure)
what does dalton’s law of partial pressures state?
The total pressure of a system of multiple gases is equal to the sum of the partial pressures exerted by each gas
what is a mole fraction? what is the equation to find mole fraction? how does this relate to partial/total pressures?
mole fraction = ratio of moles of a given substance to the total moles (denoted X)
X = moles of interest / total moles
if we multiply the total pressure by the mole fraction of a gas, we get the partial pressure of a gas
what is the ideal gas law equation? what do the variables mean here?
PV = nRT
n= # moles of gas
R = constant (0.08206 L atm/mol K)
T/F: the ideal gas law is used for scenarios where there is a change involved (initial/final conditions)
false! no change involved in the system when applying ideal gas law
T/F: dalton’s law of partial pressures does not involve a change in the system
true. no change in the system here!
what are 2 special uses of the ideal gas law? explain
- solving for density (d = PM/RT where M= molar mass)
- finding molar mass (PVM = mRT where M= molar mass, m= mass)
what is graham’s law equation? establishes a relationship between __ and ___.
what do the variables mean? how must we assign the variables here?
r1/r2 = √ M2/M1
relationship between molar mass and rate/speed of gas molecules
r1 = rate of gas 1 (gas 1 always has to be LIGHTER gas!)
r2 = rate of gas 2
M2 = molar mass of gas 2
M1 = molar mass of gas 1
when we solve a problem using graham’s law equation, what does the answer tell us?
how much faster gas 1 is than gas 2
what equation accounts for gas deviation from ideal behavior? what 2 variables does it adjust and why?
van der waals equation
adjusts 1) pressure: molecules do in fact attract and repel each other in real life
2) volume: molecules in real life DO occupy some tiny amount of space
when in a problem do you use the van der waals equation? key word to look out for?
when gases are under “non ideal conditions”
what do the variables a and b in the van der waals equation mean?
they are both constants specific to individual gases (will be provided don’t worry)
