Gas Phase (8) Flashcards
Gas pressure units
1atm = 760mmHg = 760 torr = 101.325 kPa
STP conditions
273K (0°C) and 1 atm
Standard conditions
298K (25°C) and 1 atm , 1M
Ideal gas Law
PV = nRT
R = 8.2x 10^-2 or 8.314
1 mole of STP
22.4L
Avagadro’s principle
all gases at a constant temperature and pressure occupy volumes that are directly proportional to the number of moles of gas present
n /V = k or n1 / V1 = n2 / V2
Boyle’s Law
a special case of ideal gas law for which temperature and number of moles are held constant; it shows an inverse relationship between pressure and volume.
PV = k or P1 V1 = P2 V2
Charle’s Law
states that at constant pressure, the volume of gas is proportional to its absolute temperature in kelvins.
V/T = k. or V1 / T1 = V2 / T2
Dalton’s law of partial pressure
states that individual gas components of a mixture of gases will exert individual pressures in proportional to their mole fractions. The total pressure of a mixture of gas is equal to the sum of the partial pressure of the system
Ptotal = Pa + Pb + Pc…
Pa = Xa Ptotal
Xa = moles of gas A / total moles of gas
Henry’s Law
the amount of gas dissolved in the solution is directly proportional to the partial pressure of that gas at the surface of a solution.
Average kinetic energy of gas particle
KE = 1/2mv^2 = 3/2KbT
Kb = Boltzmann constant = 1.38 x 10^-23
Gas particle speed
The higher the temperature, the faster it moves
The larger the molecules, the slower it moves
Graham’s Law
describes the behavior of gas diffusion or effusion, stating that gas with lower molar mass will diffuse or effuse faster than gases with higher molar masses at the same temperature.
Effusion
when gas moves through a small hole under pressure.
Real gases
At high Pressure, the temperature and volume is low
