Chem Q? really need help!?

Question

( both at 60degreesC)

benzene, C6H6
density= 0.877 g/ml
vapor pressure= 384 torr
formula weight= 78.1 g/mol


What is the mole fraction of benzene?

toluene, C6H5CH3
density = 0.867 g/mL
vapor pressure =133 torr
formula weight= 92.2 g/mol

which of the following will most readily dissolve in a mixture of toluene and benzene?
C2H5OH, PCL5, or HCCL3?

Does Benzene or Toluene have a higher boiling point?

Answer 1

ok.. I'm assuming you have only benzene and toluene together in a solution. if this is not the case, please restate the question...

the vapor pressure of benzene = 384 torr, vapor pressure of toluene of 133 torr. total vapor pressure = 384 + 133 torr = 517 torr

so mole fraction of benzene = P benzene / P total = 384/517
and mole fraction toluene = 1 - 384/517

benzene and toluene are both non polar solvents. ethanol and chloroform are both polar compounds and are probably not very soluble in benzene/toluene. Phosphorus pentachloride is non polar and therefore will probably be soluble in the mix.

bp benzene = 80 C, bp toluene = 111 C