5HC - Chemical Engineering Thermodynamics - October 1998
Part A (20 x 2 = 40 Marks) Answer All Questions
Part B (5 x 12 = 60 Marks)
(b) Derive Vander Waals equation of state
(c) Derive an expression for the efficiency of Carnot cycle and show it is independent of the working fluid
(b) A triple stage compressor takes air at the rate of 5 kg/min at 150 kPa and 298 K and delivers at a pressure of 6000 kPa. If the index of compression is 1.3, what is the minimum driving power required if the mechanical efficiency is 80%.
(c) 1 kmol of methane is stored in a container of 0.12 m3 volume. What is the pressure using
(i) Ideal gas law (ii) Redlich-Kwong equation (iii) Vander Waals equation.
Given Z = 0.83, Pc = 46 bar, Tc = 190 K
(d) A Carnot refrigerator is used to maintain a space at 0oC while the outside temperature is 25oC. Find the C.O.P., mass of refrigerant required and power required if the capacity is one ton.
(b) (i) Write a brief note on prediction of activity coefficients for binary system
(ii) Prove: (¶ CP/¶ P)T = -T(¶ 2V/¶ T2)P
(b) X-Y form azeotrope at 25oC containing 80% 'X'. Find Van Laar consatants. The vapor pressure of 'X' and 'Y' at 25oC is 700 and 710 mm Hg. Total pressure is 760 mm Hg. What is the composition of a vapor in equilibrium with liquid conatining 30% 'X'.
(c) How will you use the correlatory methods to check whether the vapor liquid equilibrium data, say, for a binary system determined experimentally are accurate? (8)
(d) Write a short note on Wilson equation (4)
(b) For a reaction A Û 2B, the equilibrium constant at 500oC is 0.3. The standard heat of reaction is 500 kCal/kmol. Calculate, making suitable assumptions, the equilibrium constant at 200oC.
(c) What are the criteria of phase equilibrium
(d) What are homogeneous and heterogeneous chemical reactions? Explain them with suitable examples.