A mixture of 80 mol. % ethanol (1) the balance cyclohexane (2) enters a flash separator at a

pressure of 100 kPa and temperature of half way between the bubble and dew conditions °C.

a. Balance the flash calculation assuming Raoult's law behavior (i.e., calculate the

composition and total quantity of the liquid and vapor phases).

b. Balance the flash calculation assuming the mixture follows the yar Laar activity

coefficient fits of a = 2.102, B = 1.729.

c. Continuing from the non-ideal behavior in part b, the flash separator is operated a

P = 25 kPa, and the vapor composition is 60 mol. % ethanol. At what temperature is

the flash separator operated?