Problem 11-22

This curve shows a "negative deviation" because the actual curve is lower than the theoretical (linear) curve. A negative deviation is characteristic of strong intermolecular interactions between compounds A and B. The consequences are as follows:
a. True: Negative deviation.
b. True: Strong intermolecular forces = exothermic heat of the solution.
c. True: Intermolecular forces of the mixture stronger than those present in pure solvents.
d. True: If you look at the graph, the vapor pressure of B is higher than that of A, so B is more volatile.
e. False: Since the vapor pressure of the mixture is lower than that of A or B, it is also less volatile (therefore higher boiling point). The higher the vapor pressure of a solution, the closer it is to its boiling point.