Chemical Engineering Thermodynamics I — Summer 2023

Discuss the state and properties of thermodynamics system.

It is desired to compress isothermally one kmol of ammonia from initial state of 30 m3 / kmol and 300 Kto final state of 5 m3 / kmol. It is known that the ammonia obey the relation as given below. a a (P+ )(V−b) = RT and dU = CdT+ dV V2 v V2 where a = 423.3 kPa / (m3/kmol)2, b = 0.0373 m3 / kmol, R = 8.314 kJ/kmol K. Calculate heat and work interaction with compression process.

Show that C – C = Rfor an ideal gas. P V

Calculate the molar volume of ammonia at 373 Kand 10 bar using (i) The van der Waals equation; given that, a = 4.225 lit2 bar/mol2 and b = 0.0371 lit/mol. (ii) The Redlich – Kwong equation; given that, the critical temperature is 405.5 Kand the critical pressure is 112.8 bar for ammonia.

The ideal gas equation (ii) The Redlich – Kwong equation (iii) The generalized virial coefficient correlation. Take: T = 405.7 K, P = 112.8 bar and  = 0.253 C C

Amass of 500 gm of gaseous ammonia is contained in a 30,000 cm3 vessel immersed in a constant temperature bath at 65 oC. Calculate the pressure of gas by each of the following.

Explain the various limiting conditions satisfied by equation of state.

Write short note on virial equation of state.

How is the Hess’s law of constant heat summation useful in thermochemical calculations?

What is the adiabatic flame temperature? How is it estimated? What influence does excess air have on its value?

Oil at 500 Kis to be cooled at a rate of 5000 kg/h in a counter-current exchanger using cold water available at 295 K. Atemperature approach of 10 Kis to be maintained at both ends of the exchanger.1 The specific heats of oil and water are 3.2 kJ/kg Kand 4.2 kJ/kg K respectively. Determine the total entropy change in the process.

Write Kelvin – Planck and Clausius statements.

Asteel casting (C = 0.88 kJ/kg K) at a temperature 725 Kand P weighing 35 kg is quenched in oil (C = 2.50 kJ/kg K) at 275 K. If P there are no heat losses and final temperature achieved by casting and oil is 300 K. Calculate the mass of oil.

Discuss effect of temperature on standard heat of reaction.

What is the change in entropy when 1- kmol of an ideal gas at 335 K and 10 bar is expanded irreversibly to 300 Kand 1 bar? Take C = P 29.3 kJ/kmol K.

Differentiate between reference properties, energy properties, and derived properties.

How would you obtain the Clapeyron equation from Maxwell’s equations? What are the assumptions involved in the derivation of Clausius – Clapeyron equation from the Clapeyron equation?

The coefficient of compressibility and coefficient of volume expansion of mercury at 273 Kand 1 bar are 3.9  10 – 6 (bar)-1 and 1.8  10 – 4 K-1 respectively. Calculate Cv for mercury given that Cp = 0.14 kJ/kg Kand density = 13.569  103 kg/m3.

Calculate vapour pressure of water at 363 K, if the vapour pressure at 373 Kis 101.3 kPa. The mean heat of vaporization in this temperature range is 2275 kJ/kg.

Discuss the different types of thermodynamic diagram with neat sketch and also, list their respective fields of application.

Derive the equation of continuity for control volume.

Discuss the construction and working of ejector.

Discuss vapor compression cycle with neat sketch.

What are the desirable properties of a refrigerant?

Explain the working principle of a heat pump.

The maximum velocity attainable for isentropic flow of fluid in a uniform cross section pipe is equal to speed of sound in the fluid.