Problem 1 - During a soft drink bottling process, the soft drink is carbonated using CO₂. Each 1-liter bottle of soft drink requires 0.62 g of CO₂ for the desired level of carbonation. The CO₂ is supplied from very high pressure tanks held in a "hot box" at 61°C. The fully charged tanks come from the vendor at 3735 psig, and are considers "empty" and returned to the vendor for refilling when the pressure gauge reads 60 psig.

Critical properties of CO₂:             T_c = 304.2 K                         P_c = 72.9 atm

a. What mass fraction of the CO2 originally supplied in each tank is unused when the tank is returned?

b. If the tank volume is 2 ft³, how many 1-liter soft drink bottles can be carbonated by each tank?

Problem 2 - In a single stage flash operation, the liquid feed mixture of acetone and acetic acid at high pressure and temperature flows to a flash tank where the pressure is rapidly dropped, as shown in the figure below. The liquid and gas phase exit the tank in equilibrium with each other at total pressure of 0.355 atm absolute. A sample of the gas stream is analyzed and determined to contain 0.813 mol fraction acetone.

a. Determine the temperature of the streams exiting the flash, and the partial pressures of both components in the gas phase.

b. Determine the total molar flow rates n₁ and n₂ of the streams exiting the flash tank.

Antoine Equation constants: log₁₀p* = A - (B/T+C), p* in mm Hg, T in ^oC

Problem 3 - To study hydrocarbon solubilities in water related to possible groundwater contamination, the experimental apparatus shown below is used. In this experiment, ethane (C₂H₆) is sparged, or bubbled, through a column of water such that the exiting gas stream is in equilibrium with the liquid. The absolute pressure of the exiting stream is measured to be 1.87 atm, and the temperature of the liquid is measured to be 18.5°C. A sample of the liquid is analyzed and found to contain 0.124 g ethane/liter.

Determine the Henry's law constant H_e (atm/mol fraction) for ethane in water at 18.5°C.