# UPTU Previous Question Papers

## 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 P2 = 6.0 bar in a steady flow compressor. Delivered mechanical power is 98.8 kW. Temperature and velocities are:

T1= 300 K T2 = 520 K

U2 = 10ms_1 U2 = 3.5 ms-1

Estimate the rate of heat transfer from the compressor. Assume for air that Cp = 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 V0 – 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 cm3 mol-1

C = -26,000 cm6mor2

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 m3 of C02 and 0.3 m3 of N2 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 yt

(e) If -^7 = (-2.6 x1 – 1.8x2 ) xjx2

Find expressions for In yj and In y2 .

(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 C02, CO and 02 at 3000 K, 0.1 MPa pressure. Determine the equilibrium composition. Data : K=0.1089