Additional problems, Chapter 5

1. Calculate the freezing point and boiling point depression constants for benzene.  See table 5.2 for answers..

2.  Ethanol and methanol form very nearly ideal solutions.  At 20 ^oC, the vapor pressure of ethanol is 5.93 kPa, and that of methanol is 11.83 kPa.  (a) Calculate the mole fractions of methanol and ethanol in a solution obtained by mixing 100 g of each. (b) Calculate the partial pressures and the total vapor pressure of the solution.  (c)  Calculate the mole fraction of methanol in the vapor.  Answer:  (a)0.590, 0.410, (b) 6980, 2430, 9410, Pa, (c) 0.742.