SBI PO - Chemical Engineering Thermodynamics 1000+ MCQ [Solved] PDF Download

1. What is the number of degree of freedom for a system of two miscible non-reacting species in vapor-liquid equilibrium forming an azeotrope?
A. 0
B. 2
C. 1
D. 3
Answer : C

2. The variation of heat of reaction with temperature at constant pressure is given by the __________ law.
A. Kelvin's
B. Antoines
C. Kirchoffs
D. None of these
Answer : C

3. In jet refrigerators, the refrigerating fluid is practically always
A. Water
B. Ammonia
C. Freon
D. Brine
Answer : A

4. In vapour compression refrigeration system, if the evaporator temperature and the condenser temperatures are -13°C and 37°C respectively, the Carnot COP will be
A. 5.2
B. 6.2
C. 0.168
D. Data insufficient, can't be found out
Answer : A

5. Entropy change of the reaction, H2O (liquid) ? H2O (gas), is termed as the enthalpy of
A. Solution
B. Vaporisation
C. Formation
D. Sublimation
Answer : B

6. __________ calorimeter is normally used for measuring the dryness fraction of steam, when it is very low.
A. Bucket
B. Throttling
C. Separating
D. A combination of separating & throttling
Answer : D

7. Pick out the wrong statement.
A. A closed system does not permit exchange of mass with its surroundings but may permit exchange of energy.
B. An open system permits exchange of both mass and energy with its surroundings
C. The term microstate is used to characterise an individual, whereas macro-state is used to designate a group of micro-states with common characteristics
D. None of the above
Answer : D

8. (?T/?P)H is the mathematical expression for
A. Specific heat at constant pressure (C_p)
B. Specific heat at constant volume (C_v)
C. Joule-Thompson co-efficient
D. None of these
Answer : C

9. Pick out the wrong statement.
A. The values of (?P/?V)_T and (?²P/?V²)_T are zero for a real gas at its critical point
B. Heat transferred is equal to the change in the enthalpy of the system, for a constant pressure, non-flow, mechanically reversible process
C. Thermal efficiency of a Carnot engine depends upon the properties of the working fluid besides the source & sink temperatures
D. During a reversible adiabatic process, the entropy of a substance remains constant
Answer : C

10. All gases above its inversion temperature, in a throttling process will show
A. A heating effect
B. No change in temperature
C. A cooling effect
D. Either (A) or (C)
Answer : A

11. In an ideal solution, the activity of a component equals its
A. Mole fraction
B. Fugacity at the same temperature and pressure
C. Partial pressure
D. None of these
Answer : A

12. C_p of a gas at its critical temperature and pressure
A. Becomes zero
B. Becomes infinity
C. Equals 1 kcal/kmol °K
D. Equals 0.24 kcal/kmol °K
Answer : B

13. Isotherm on an enthalpy-concentration diagram, for an ideal solution will be a
A. Straight line
B. Sine curve
C. Parabola
D. Hyperbola
Answer : A

14. In polytropic process (PVⁿ = constant), if n = 1; it means a/an __________ process.
A. Adiabatic
B. Reversible
C. Isothermal
D. None of these
Answer : C

15. In the ammonia synthesis reaction, N₂ + 3H₂ ? 2NH₃ + 22.4 kcal, the formation of NH₃ will be favoured by
A. High temperature
B. Low pressure
C. Low temperature only
D. Both low temperature and high pressure
Answer : D

16. Consider the reaction, C + O₂ ? CO₂; ?H = - 94 kcal. What will be the value of ?H for the reaction CO₂ ? C + O₂?
A. -94 kcal
B. +94 kcal
C. > 94 kcal
D. < -94 kcal
Answer : B

17. Which of the following is not an intensive property?
A. Molar heat capacity
B. Internal energy
C. Viscosity
D. None of these
Answer : B

18. Which is a state function?
A. Specific volume
B. Work
C. Pressure
D. Temperature
Answer : B

19. In a homogeneous solution, the fugacity of a component depends upon the
A. Pressure
B. Composition
C. Temperature
D. All (A), (B) and (C)
Answer : D

20. In which of the following reaction equilibrium, the value of equilibrium constant K_p will be more than is K_c?
A. 2HI ? H₂ + I₂
B. N₂O₄ ? 2NO₂
C. 2SO₂ + O₂ ? 2SO₃
D. None of these
Answer : B

21. The third law of thermodynamics states that he
A. Heat capacity of a crystalline solid is zero at absolute zero temperature
B. Heat transfer from low temperature to high temperature source is not possible without external work
C. Gases having same reduced properties behaves similarly
D. None of these
Answer : A

22. What is the value of maximum COP in case of absorption refrigeration, if refrigeration provided is at temperature, T_R (where, T₁ and T₂ are source & surrounding temperatures respectively.)?
A. T_R/(T₂ - T_R) × (T₁ - T₂)/T₁
B. T_R/(T₂ - T_R) × T₁/(T₁ - T₂)
C. T_R/(T₁ - T_R) × (T₁ - T₂)/T₁
D. None of these
Answer : A

23. Degree of freedom of a system consisting of a gaseous mixture of H2 and NH3 will be
A. 0
B. 1
C. 2
D. 3
Answer : D

24. A reasonably general expression for vapourliquid phase equilibrium at low to moderate pressure is ?_i y_i P = Y_i x_if_i° where, ? is a vapor fugacity component, Y_i is the liquid activity co-efficient 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
A. Temperature only
B. Temperature and pressure only
C. Temperature, pressure and liquid composition x_i only
D. Temperature, pressure, liquid composition x_i and vapour composition yi
Answer : C

25. Maximum work that could be secured by expanding the gas over a given pressure range is the __________ work.
A. Isothermal
B. Adiabatic
C. Isentropic
D. None of these
Answer : A

26. Extensive properties of a thermodynamic system depend upon the __________ of the system.
A. Specific volume
B. Temperature
C. Mass
D. Pressure
Answer : C

27. A system is said to be isopiestic, if there is no __________ change.
A. Temperature
B. Pressure
C. Volume
D. None of these
Answer : B

28. All gases during throttling process at atmospheric temperature and pressure show a cooling effect except
A. CO₂
B. H₂
C. O₂
D. N₂
Answer : B

29. Refrigerants commonly used for domestic refrigerators are
A. Ethyl chloride or methyl chloride
B. Freon-12
C. Propane
D. NH3 or CO2
Answer : A

30. An isolated system can exchange __________ with its surroundings.
A. Matter
B. Energy
C. Neither matter nor energy
D. Both matter and energy
Answer : C

31. At 60° C, vapour pressure of methanol and water are 84.562 kPa and 19.953 kPa respectively. An aqueous solution of methanol at 60° C exerts a pressure of 39.223 kPa; the liquid phase and vapour phase mole fractions of methanol are 0.1686 and 0.5714 respectively. Activity co-efficient of methanol is
A. 1.572
B. 1.9398
C. 3.389
D. 4.238
Answer : A

32. Joule-Thomson experiment is
A. Isobaric
B. Adiabatic
C. Isenthalpic
D. Both (B) & (C)
Answer : D

33. The following heat engine produces power of 100,000 kW. The heat engine operates between 800 K and 300 K. It has a thermal efficiency equal to 50% of that of the Carnot engine for the same temperature. The rate at which heat is absorbed from the hot reservoir is
A. 100,000 kW
B. 160,000 kW
C. 200,000 kW
D. 320,000 kW
Answer : D

34. A system undergoes a change from a given initial state to a given final state either by an irreversible process or by a reversible process, then (where, ? S₁ and ? S_R are the entropy changes of the system for the irreversible and reversible processes respectively)
A. ? S₁ is always < ? S_R
B. ? S₁ is sometimes > ? S_R
C. ? S₁ is always > ? S_R
D. ? S₁ is always = ? S_R
Answer : C

35. Which of the following is not affected by temperature changes?
A. Fugacity
B. Activity co-efficient
C. Free energy
D. None of these
Answer : D

36. The reaction A (l) ? R(g) is allowed to reach equilibrium conditions in an autoclave. At equilibrium, there are two phases, one a pure liquid phase of A and the other a vapor phase of A, R and S. Initially A alone is present. The numbers of degrees of freedom are:
A. 1
B. 2
C. 3
D. 0
Answer : B

37. A gas performs the maximum work, when it expands
A. Non-uniformly
B. Adiabatically
C. Isobarically
D. Isothermally
Answer : C

38. Pick out the wrong statement.
A. System (of partially miscible liquid pairs), in which the mutual solubility increases with rise in temperature, are said to possess an upper consolute temperature
B. Systems, in which the mutual solubility increases with decrease in temperature, are said to possess lower consolute temperature
C. Nicotine-water system shows both an upper as well as a lower consolute temperature, implying that they are partially miscible between these two limiting temperatures
D. None of these
Answer : D

39. If the heat of solution of an ideal gas in a liquid is negative, then its solubility at a given partial pressure varies with the temperature as
A. Solubility increases as temperature increases
B. Solubility increases as temperature decreases
C. Solubility is independent of temperature
D. Solubility increases or decreases with temperature depending on the Gibbs free energy change of solution
Answer : B

40. Which of the following equations is used for the prediction of activity co-efficient from experiments?
A. Van Laar equation
B. Margules equation
C. Wilson's equation
D. All (A), (B) and (C)
Answer : D

41. Molar heat capacity of water in equilibrium with ice at constant pressure is __________ Kcal/kg mole. °K
A. 0
B. ?
C. 50
D. 100
Answer : B

42. The partial molar enthalpy of a component in an ideal binary gas mixture of composition Z, at a temperature T and pressure P, is a function only of
A. T
B. T and P
C. T, P and Z
D. T and Z
Answer : B

43. For an ideal gas, the enthalpy
A. Increases with rise in pressure
B. Decreases with rise in pressure
C. Is independent of pressure
D. Is a path function
Answer : C

44. Which of the following is Clausius-Clapeyron Equation for vaporisation of an ideal gas under the condition that the molar volume of liquid is negligible compared to that of the vapor?
A. d ln p/dt = H_vap/RT²
B. d ln p/dt = RT²/H_vap
C. dp/dt = RT²/H_vap
D. dp/dt = H_vap/RT²
Answer : A

45. When liquid and vapour phases of one component system are in equilibrium (at a given temperature and pressure), the molar free energy is
A. More in vapour phase
B. More in liquid phase
C. Same in both the phases
D. Replaced by chemical potential which is more in vapour phase
Answer : C

46. A system in which there is exchange of energy but not of mass, is called a/an __________ system.
A. Isolated
B. Open
C. Insulated
D. Closed
Answer : D

47. C_p - C_v = R is valid for __________ gases.
A. Ideal
B. Very high pressure
C. Very low temperature
D. All of the above
Answer : A

48. Out of the following refrigeration cycles, which one has maximum COP?
A. Air cycle
B. Carnot cycle
C. Ordinary vapor compression cycle
D. Vapor compression with a reversible expansion engine
Answer : B

49. A refrigerator may be termed as a
A. Heat pump
B. Heat engine
C. Carnot engine
D. None of these
Answer : A

50. At constant temperature and pressure, for one mole of a pure substance, the ratio of the free energy to the chemical potential is
A. Zero
B. One
C. Infinity
D. Negative
Answer : B