Chemical Engineering Thermodynamics

31. A reasonably general expression for vapour-liquid phase equilibrium at low to moderate pressure is φ_i y_i P = Y_i x_if_i° where, Φ is a vapor fugacity component, Y_i is the liquid activity coefficient and f_i° is the fugacity of the pure component i. the K_i value (Y_i = K_i x_i) is therefore, in general a function of

1. Temperature only
2. Temperature and pressure only
3. Temperature, pressure and liquid composition xi only
4. Temperature, pressure, liquid composition xi and vapour composition yi

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32. A refrigeration cycle is a reversed heat engine. Which of the following has the maximum value of the co-efficient of performance (COP) for a given refrigeration effect?

1. Vapor compression cycle using expansion valve
2. Air refrigeration cycle
3. Vapor compression cycle using expansion engine
4. Carnot refrigeration cycle

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33. A refrigeration cycle is the same as a _________ cycle,

1. Turbine
2. Heat engine
3. Reversed heat engine
4. None of these

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34. A refrigerator may be termed as a

1. Heat pump
2. Heat engine
3. Carnot engine
4. None of these

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35. A refrigerator works on the principle of _________ law of thermodynamics.

1. Zeroth
2. First
3. Second
4. Third

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36. A solid is transformed into vapour without going to the liquid phase at

1. Triple point
2. Boiling point
3. Below triple point
4. Always

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37. A solid metallic block weighing 5 kg has an initial temperature of 500°C. 40 kg of water initially at 25°C is contained in a perfectly insulated tank. The metallic block is brought into contact with water. Both of them come to equilibrium. Specific heat of block material is 0.4 kJ.kg^-1. K^-1. Ignoring the effect of expansion and contraction and also the heat capacity to tank, the total entropy change in kJ.kg^-1, K^-1 is

1. -1.87
2. 0
3. 1.26
4. 3.91

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38. A solute distributes itself between two non-miscible solvents in contact with each other in such a way that, at a constant temperature, the ratio of its concentrations in two layers is constant, irrespective of its total amount". This is

1. The distribution law
2. Followed from Margules equation
3. A corollary of Henry's law
4. None of these

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39. A system in which there is exchange of energy but not of mass, is called a/an _________ system.

1. Isolated
2. Open
3. Insulated
4. Closed

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40. A system is said to be at equilibrium, if the entropy of the system has reached _________ value.

1. Minimum
2. Zero
3. Maximum
4. None of these

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