EXAMPLE: A container has 16.7 g O2, 8.1 g H2 and 35.2 g N2 and contains a total pressure of 0.83 atm. Calculate the mole
CONCEPT: PARTIAL PRESSURES OF GASES _________________ Law states that in a container of unreacting gases, the total pressure of the container is the sum of the partial pressures of the individual gases.
PTOTAL = PGas 1 + PGas 2 + PGas 3 + …… The total pressure is due to the total number of moles. • The partial pressure of each gas molecule is the total pressure multiplied by the mole fraction of each gas molecule.
PGas1 = ( X Gas 1 ) • ( PTotal ) X = ___________________________
X Gas1 =
(molesGas1) ( TotalMoles)
PGas1 = ___________________________
EXAMPLE: A container has 16.7 g O2, 8.1 g H2 and 35.2 g N2 and contains a total pressure of 0.83 atm. Calculate the mole fraction of O2 and its partial pressure.
PRACTICE: A gas mixture with a total pressure of 812 mmHg contains the following gases at with their partial pressures: Cl2 = 210 mmHg, H2 = 180 mmHg, CO2 = 215 mmHg. If argon gas is also present calculate its mole fraction.
