Homework #9

Chapter 6:    6.22, 27, 28, 30, 35, 37, 40, 91 (3rd edition: ??)



Hints/comments:

22) The boiling point diagram is to be drawn for a total pressure of 1 bar. A mixture of benzene and toluene will boil when its total vapor pressure is 1 bar. For each temperature, find the mole fractions (of benzene) in the liquid and vapor phases for which the total vapor pressure is 1 bar. Note, it's best to fit the bubble pt and dew pt lines to smooth curves, i.e., polynomials, to do this evaluation.

27) Hint for part c: consider the 2 temperatures in the two-phase region that correspond to all liquid and all vapor, respectively, at the initial composition.

30) Also calculate the Henry's law constant for EtOH in chloroform and for chloroform in EtOH. Then calculate the activity coefficients of ethanol and chloroform based on the Henry's law standard state.

91) On a plot of temperature vs. composition, record the break points (inflections) and arrests (plateaus). Connect the arrests with horizontal lines, exentending them as appropriate. Draw smooth curves to connect the break points ending at pure metal (or compound) and eutectic.