2. CHE 205

3. $200 $400 $600 $800 $1000 Vapor/Liquid Equilibrium Energy Balances Multiphase Systems Nonreactive Processes $600

4. How can you tell which of two components is more volatile?

5. What can you say about the bubble point and dew point temperatures of a mixture of two components A and B (T ⁰ b,A < T ⁰ b,B )? What about the compositions of the first bubble and last drop of mixture?

6. Explain why a soda can fizzes when it is opened

7. Draw the temperature plot for heating pure cyclohexane from 20 C to 100 C at a pressure of 1 atm. State what is happening in each region of the curve.

8. Write the equations to solve for the temperature and composition of a liquid in equilibrium with a vapor that is 30 mole% acetone-70 mole% ethanol at 1 atm. Is this a bubble- point or dew-point calculation? List vapor pressures as a variable and state where you would find them.

9. What can you say about the enthalpy of a system of air at 600 ⁰ F and 1 atm? The value given in Table B.9 is 3719 BTU/lbmol

10. Cancel the terms of the energy balance of the following system and explain if the remaining terms are positive or negative IsothermalCondenser m 1 kg H 2 O (v)/hr P = 20 bar T = 250 C m 2 kg H 2 O (v)/hr P = 40 bar, sat’d m 3 kg H 2 O (l)/hr

12. Complete the following table for water StateT (°C)P (bar)V (m 3 /kg) U (kJ/kg) Table Vapor50Sat’d Liquid941 VaporSat’d0.538 45040

13. One thousand kilograms per hour of steam drives a turbine. The steam enters the turbine at 60 bar and 450C. The turbine delivers shaft work at a rate of 70 kW and the heat loss is 20 kW. Calculate the final temperature of the steam if the final pressure is 0.5 bar.

14. If a pump is 70 % efficient, how many kW are necessary to pump water flowing at 10 kg/s from a lake at 1 bar to an outlet 75 m above the lake at 5 bar, if the outlet pipe has a 4 cm ID?

15. Define a colligative solution property? Name 3 of them.

16. Without using your book, what is the definition of bubble-point and dew-point temperatures? What assumptions must be made to apply Raoult’s or Henry’s Laws?

17. What is the dew point and composition of a mixture of 70% 1-propanol with the rest 1-pentanol in the vapor phase?

18. Given the following Txy diagram for styrene in toluene at 1000 mm Hg, if a mixture with 40 mole% of styrene is fed to an evaporator what is the bubble- point temperature and the equilibrium vapor composition?

19. A gas containing O 2 is in equilibrium with liquid water containing a small amount of O 2 at 30C and 3 atm. Would you use Raoult’s Law or Henry’s Law to estimate the relationship between a.x O2 and p O2 b. x H2O and p H2O and why?

20. If HCN is taken from 25°C to 100°C, both states at 1 atm, but was carried out in such a way that the pressure varied during the heating, can you still use C p to calculate the specific enthalpy and why?

21. Estimate the heat capacity of solid CaCO 3 using Kopp’s Rule

22. Calculate the specific enthalpies of the following processes: a.N 2 (25°C to 700°C) b.H 2 (800°F to 225°F)

23. Draw the process path of n- pentane going from a solid at - 150°C and 0.5 atm to a vapor at 100°C and 4.0 atm. List where you would find the information to calculate ΔH for each step, but don’t calculate any of them.

25. Suppose the formula was used to calculate the specific enthalpy change for a change in temperature and pressure for a.An ideal gas b.A highly nonideal gas c.A liquid For which situation is the formula exact and which would have error?