Sathyabama University 2008 B.Tech Chemical Engineering Thermodynamics - Question Paper

SATHYABAMA UNIVERSITY

(Established under section 3 of UGC Act, 1956)

 

Course & Branch: B.Tech - Chemical (Part Time)

Title of the paper: Chemical Engineering Thermodynamics

Semester: III Max. Marks: 80

Sub.Code: 619PT302 (2007 JAN) Time: 3 Hours

 

PART A (10 x 2 = 20)

Answer All the Questions

1. What is the criteria for exactness of a differential expression.

2. What is significance of Maxwells Equations?

 

3. What is the clearance volume in compressures?

 

4. Distinguish between heat engine and heat pump.

 

5. Draw P-T-x-y diagram for low boiling point azeotrope.

 

6. What is the criterion for Phase equillibria?

 

7. What are called excess properties?

 

8. Define activity and activity coefficient.

 

9. State Vants Hoffs equations.

 

10. A gas mixture containing 2 moles nitrogen, 7 moles hydrogen and 1 mole ammonia initially id undergoing the following reaction N₂ + H₂ NH₃. Drive an expression for mole fraction of ammonia in terms of Reaction coordinate.

 

PART B (5 x 12 = 60)

Answer All the Questions

11. Explain the methods available for determination of partial molar properties.

(or)

12. Using the residual volume method compute the fugacity of propane at 11.87 bar and 37.7C.

Pressure(bar)	1.72	3.44	6.39	10.32	12.04
Specific Vol(m3/kg)	0.33	0.16	0.075	0.046	0.032

13. (a) Explain in detail about Ejectors. (4)

(b) 500kg/hr of methane is compressed from 2 bar, 2.77.7K to 8
bar. What is the power requirement when

(i) Compression is isothermal and methane behaves as an
ideal gas.

(ii) Compression is adiabatic and methane behaves as an ideal gas. g = 1.4. (8)

(or)

14. Show that the multistage compressor operation the total work requirement is a minimum when the work in all stage is the same, provide that the gas is cooled to the initial temperature after stage. [ S.T.P² = P₂P₁]

 

15. With proper phase diagrams Pxy, Txy and y-x distinguish between minimum and maximum boiling azeotropes.

(or)

16. (a) Explain about Gibbs phase rule and discuss about its
applications.

(b) Define Raoults Law and discuss about its applications in phase equillibria.

 

17. Drive Gibbs Duhem equation and show that the equation

V = 90 x 10 ³X₁+50 x10 ³X₂+X₁ X₂(6 x 10 ³ X₁ + 9 x 10 ³X₂)

Sttisfies Gibbs Duhem equation.

(or)

18. At atmospheric pressure ethyl acetate and ethyl alcohol forms an azeotrophic mixer containing 53.9 mol% of ethyl acetate boiling at 72 C where vapour pressure of pure liquids are 587 and 686mmHg respectively. Calculate Margules equation constants.

 

19. Drive the relation between the mole fraction of the species present in the reaction and the reaction coordinate .

(or)

20. Discuss the relationship between free energy change and equilibrium constant. Explain how do you estimate equilibrium constant K.