Que-2-A laboratory apparatus includes two water-filled compartments, A and B, separated by a semipermeable membrane 2 mm thick. The entire system is allowed to equilibrate with 1 ppm phenol. At time t = 0, additional phenol is added to compartment A, raising its concentration to 10 ppm
. a. Write the equation that describes the concentration of phenol as a function of time and the distance x from compartment A. Treat the membrane as if it were infinitely thick, and assume the phenol concentration in compartments A and B does not change significantly over time.
b. Given a water temperature of 20 °C, estimate the diffusion coefficient for phenol in water using both the WilkeâChang relationship (with the HaydukâLaudie value of X) and the HaydukâLaudie relationship. How much do the two values differ?
c. Use software to plot the concentration profile of phenol across the thickness of the membrane 1 minute after the start of the experiment. Use the WilkeâChang value of D.
d. Treating the membrane as semi-infinite is valid until the concentration it predicts at the interface with compartment B begins to deviate significantly from the correct value. What is the correct boundary condition at that interface, and at what time will your solution from part (a) deviate from this value by more than 5%?
Que-2-A laboratory apparatus includes two water-filled compartments, A and B, separated by a semipermeable membrane 2 mm thick. The entire system is allowed to equilibrate with 1 ppm phenol. At time t = 0, additional phenol is added to compartment A, raising its concentration to 10 ppm
. a. Write the equation that describes the concentration of phenol as a function of time and the distance x from compartment A. Treat the membrane as if it were infinitely thick, and assume the phenol concentration in compartments A and B does not change significantly over time.
b. Given a water temperature of 20 °C, estimate the diffusion coefficient for phenol in water using both the WilkeâChang relationship (with the HaydukâLaudie value of X) and the HaydukâLaudie relationship. How much do the two values differ?
c. Use software to plot the concentration profile of phenol across the thickness of the membrane 1 minute after the start of the experiment. Use the WilkeâChang value of D.
d. Treating the membrane as semi-infinite is valid until the concentration it predicts at the interface with compartment B begins to deviate significantly from the correct value. What is the correct boundary condition at that interface, and at what time will your solution from part (a) deviate from this value by more than 5%?