Gas Phase Flashcards
mathematical relationships between the pressure measurements
1 atm = 760 mmHg = 760 torr = 101.325 kPa
standard temp and pressure
273 K (0°C) and 1 atm
standard stage conditions/when they’re used
298 K, 1 atm, 1 M
standard enthalpy, entropy, free energy changes, and electrochemical cell voltage
ideal gas definition
hypothetical has w no IMF and occupy no volume
when do real gases deviate from ideal behavior?
high pressure and low volumes
ideal gas law
PV=nRT
density of ideal gas
ρ = m/V = PM/RT
M is molar mass
density under nonstandard conditions
ρ = m/(V^2)
combined gas law
(P1V1)/(T1) = (P2V2)/(T2)
STP volume of one mole of gas
22.4 L/mol
molar mass at STP
M = (ρSTP)(22.4 L/mol)
Avogadro’s principle
n/V = k
n1/V1 = n2/V2
Boyle’s Law
PV = k
P1V1 = P2V2
Charles’s Law
V/T = k
V1/T1 = V2/T2
Gay-Lussac’s Law
P/T = k
P1/T1 = P2/T2
Dalton’s law of partial pressures
total pressure is sum of all partial pressures in gaseous mixture
mole fraction of gas in a mixture
Pa = XaPt
Xa = moles of gas A/total moles of gas
equilibrium between the evap and condensation stages of an ideal gas
[A] = kH x PA
[A]1/P1 = [A]2/P2 = kH
average molecular speed
KE = 1/2•m(v^2) = 3/2•kB•T
Boltzmann constant kB
1.38 x 10^-23 J/K
root mean squared speed
urms = sqrt(3RT/M)
diffusion
movement of molecules from high to low concentration in a medium
effusion
flow of gas particles under pressure from one compartment to another through a small opening
Graham’s law
the relationship of the rates at which two gases diffuse
r1/r2 = sqrt(M2/M1)
van der Waals equation of state
[P + (n^2•a)/(V^2)] (V - nb) = nRT
accounts somewhat for deviations from ideal
