AP Chemistry
posted by Anonymous .
A 1.00L gas sample at 100°C and 600 torr contains 50% helium and 50% xenon by mass. What are the partial pressures of the individual gas?

Pick any convenient number for the total mass, then half of that is He and half is Xe.
Now find the moles.
moles = grams/molar mass.
Calculate mole fraction He and mole fraction Xe.
mole fraction He = mol He/total moles and
mole fraction Xe = mol Xe/total moles.
Finally,
PHe = mole fraction He*total P (which is 600 torr).
PXe = mole fraction Xe*total P. 
partial pressure for He: 582 torr & 18 torr for xe