Butanone, CH3CH2COCH3, has a vapor pressure of 100. Torr at 25°C; at the same temperature, propanone, CH3COCH3, has a vapor pressure of 222 Torr. What mass of propanone must be mixed with 322.0 g of butanone to give a solution with a vapor pressure of 135 Torr? Assume ideal behavior.

Answer 1

Use P_soln = X_solventP_solvent^o

That will calculate X for each solvent.
Go from there to grams of each (one is given in grams). Post your work if you get stuck.