Ch. 8: The Gas Phase Flashcards
variables that define the gaseous state
- pressure (P)
- volume (V)
- temperature (T)
- number of moles (n)
what is an ideal gas
a hypothetical gas with molecules that have no intermolecular forces and occupy no volume
ideal gas law
PV = nRT
where R = 8.21 E-2 in [L * atm] / [mol * K]
density derived from ideal gas law
p = m / V = PM / RT
were n = m (mass) / M (molar mass)
combined gas law
relationship of P, V, and T for a gas as conditions change
[P1V1] / T1 = [P2V2] / T2
how many L does 1 mole of gas occupy at STP
1 mole of ideal gas = 22.4 L at STP
Avogadro’s principle
relationship of moles and volume
n/V = k OR n1/V1 = n2/V2
number of moles of any gas is directly proportional to volume
Boyle’s law
relationship of pressure and volume
PV = k or P1V1 = P2V2
pressure and volume are inversely proportional
Charle’s law
relationship of volume and temperature
V/T = k or V1/T1 = V2/T2
volume and temperature are directly related
Gay - Lussac’s law
relationship of pressure and temperature
P/T = k or P1/T1 = P2/V2
pressure and temperature are directly related
partial pressure
pressure exerted by each individual gas in a container when those gases do not combine with each other
equation for total pressure from partial pressure
Pt = Pa + Pb + Pc …
total pressure is equal to the sum of all the partial pressures
equation for partial pressure of a gas
Pa = Xa * Pt
where Xa = moles of gas a / total moles of gas
vapor pressure
pressure exerted by evaporated particles above the surface of the liquid
equation for vapor pressure of a gas
[a] = kH * Pa
OR
[a]1/P1 = [a]2/P2 = kH
where [a] is concentration of a in sol’n, kH is Henry’s constant and Pa is the partial pressure of the gas
