# UPTU Previous Question Papers

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## VI Semester TCH Examination 2006-07

## Chemical Engineering Thermodynamics

**Note : Attempt all questions.**

** 1. Attempt any two parts of the following :**

(a) Fifty (50) kmol per hour of air is compressed from Pj = 1.2 bar to P_{2} = 6.0 bar in a steady flow compressor. Delivered mechanical power is 98.8 kW. Temperature and velocities are:

T1= 300 K T_{2} = 520 K

U2 = 10ms^{_1} U_{2} = 3.5 ms^{-1}

Estimate the rate of heat transfer from the compressor. Assume for air that C_{p} = 7/2R and that enthalpy is impendent of pressure.

(b) In a steady-state flow process 1 mol S^{-1} of air at 600 K and 1 atm is continuously mixed with 2 mol S^{-1} of air at 450 K and 1 atm. The product stream is at 400 K and 1 atm. Determining the rate of heat transfer and the rate of entropy generation for the process. Assume that air is an ideal gas with Cp = 7/ 2 R. That the surroundings are at 300 K and that kinetic and potential energy charges are negligible.

Derive relation for calculation of ideal work in a steady state flow process. What is lost work?

**2. Attempt any two parts of the following :**

(a) Calculate the fugacity of C ammonia at

= 200°C and P = | 100 atm if |

P, atm | V_{0} – cm |

20 | 1866 |

60 | 570.8 |

100 | 310.9 |

150 | 176.7 |

(b) Derive following relations :

(c) Reported values for the virial co-efficients of Isopropanol vapour at 200°C are :

B = -388 cm^{3} mol^{-1}

C = -26,000 cm^{6}mor^{2}–

Calculate V and Z for Isopropanol vapour at 200°C and 10 bar with the help of the virial equation truncated to three terms.

**3. Attempt any four parts of the following :**

(a) What is change in entropy when 0.7 m^{3} of C0_{2} and 0.3 m^{3} of N_{2} each at 1 bar and 25°C blend to form a gas mixture at the same condition? Assume ideal gases.

(b) Derive Cribbs Duhem equations.

(c) Derive fundamental property relation.

(d) Show that = Gf + RT In y_{t}

(e) If -^7 = (-2.6 x_{1} – 1.8x_{2} ) xjx_{2}

Find expressions for In yj and In y_{2} .

(f) Show that multiple phases at the same T and P are in equilibrium when the chemical potential of each constituents species in the same in all phases.

**4. Attempt any four parts of the following :**

(a) Define ideal solution. What is Lewis/Randall rule?

(b) Derive Margules equation.

(c) Define the critical point of a mixture. Show a portion of a PT diagram in the critical region.

(d) Draw P-xy and T-xy diagram for azeotropic mixture.

(e) Explain the characteristics of vapour / liquid / liquid equilibrium with help of a T-xy diagram.

(f) Show T xy and P xy diagram for binary system of immiscible liquids.

**5. Answer any two parts of the following :**

(a) Derive the following :

(>) Ew =^{0}

(ii) ;ag° = -£ag*>

(b) Develop relation for equilibrium constants for gas-phase reaction.

(c) One kilo mol of Carbon at 25°C reacts with 2 kmol of oxygen at 25°C to form an equilibrium mixture of C0_{2}, CO and 0_{2} at 3000 K, 0.1 MPa pressure. Determine the equilibrium composition. Data : K=0.1089