A closed vessel of volume 2.50 dm3 contains 100g of nitrogen (N2) and 100g of carbon dioxide (CO2) at 25 C. What are the partial pressures and mole fractions of each gas?

Answer 1

mols N2 = grams/molar mass = ?
mols CO2 = grams/molar mass = ?

Use PV = nRT, substitute EACH (mols N2 and mols CO2 separately) and find pressure of each.

You can find X two ways.
1. total mols = mols N2+mols CO2.
XN2 = mols N2/total mols
XCO2 = mols CO2/total mols.

2. Ptotal = pN2 + pCO2
XN2 = mols N2*Ptotal
XCO2 = mols CO2*Ptotal
Post your work if you get stuck.