Chemical Engineering Thermodynamics MCQ Solved Paper for SSC JE

1. For an isothermal reversible compression of an ideal gas
A. Only ?E = 0
B. Only ?H =0
C. ?E = ?H = 0
D. dQ = dE
Answer : C

2. Pick out the wrong statement
A. Phase rule variables are intensive properties
B. Heat and work are both state function
C. The work done by expansion of a gas in vacuum is zero
D. C_P and C_V are state function
Answer : B

3. Melting of wax is accompanied with __________ in entropy.
A. Increase
B. Decrease
C. No change
D. None of these
Answer : A

4. Which of the following is not an extensive property?
A. Free energy
B. Entropy
C. Refractive index
D. None of these
Answer : C

5. The equation relating E, P, V and T which is true for all substances under all conditions is given by (?E/?V)_T = T(?P/?T)_H - P. This equation is called the
A. Maxwell's equation
B. Thermodynamic equation of state
C. Equation of state
D. Redlich-Kwong equation of state
Answer : B

6. In case of the decomposition of hydroiodic acid (2HI ? H₂ + I₂), addition of H₂ (at equilibrium condition) will
A. Increase the partial pressure of I₂
B. Decrease the partial pressure of HI
C. Diminish the degree of dissociation of HI
D. None of these
Answer : C

7. The molar excess Gibbs free energy, g^E, for a binary liquid mixture at T and P is given by, (g^E/RT) = A . x₁. x₂, where A is a constant. The corresponding equation for ln y₁, where y₁ is the activity co-efficient of component 1, is
A. A . x₂²
B. Ax₁
C. Ax₂
D. Ax₁²
Answer : A

8. Which of the following is Virial equation of state?
A. (p + a/V²)(V - b) = nRT
B. PV = nRT
C. PV = A + B/V + C/V² + D/V³ + ...
D. None of these
Answer : C

9. Critical temperature is defined as the temperature above which a gas will
A. Not liquify (barring exceptions)
B. Immediately liquify
C. Never liquify however high the pressure may be
D. None of these
Answer : C

10. The unity of Planck's constant 'h' in the equation, E = hv is
A. J/s
B. J.S
C. J/kmol
D. kmol/J
Answer : B

11. The necessary and sufficient condition for equilibrium between two phases is
A. The concentration of each component should be same in the two phases
B. The temperature of each phase should be same
C. The pressure should be same in the two phases
D. The chemical potential of each component should be same in the two phases
Answer : D

12. In a reversible process
A. Tds = dE + dW
B. dE - dW = Tds
C. dW - dE = Tds
D. Tds - dW + dE >0
Answer : A

13. Free energy
A. Decreases in all spontaneous (or irreversible) processes
B. Change during a spontaneous process has a negative value
C. Remains unchanged in reversible processes carried at constant temperature and pressure
D. All (A), (B) and (C)
Answer : D

14. Those solutions in which there is no volume change upon mixing the components in the liquid state and which, when diluted do not undergo any heat change (i.e. heat of dilution is zero), are called __________ solutions.
A. Ideal
B. Real
C. Isotonic
D. None of these
Answer : A

15. Joule-Thomson Co-efficient at any point on the inversion curve is
A. ?
B. +ve
C. 0
D. -ve
Answer : C

16. Isobaric process means a constant process.
A. Temperature
B. Pressure
C. Volume
D. Entropy
Answer : B

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

18. Pick out the wrong statement.
A. Cp of monatomic gases such as metallic vapor is about 5 kcal/kg.atom
B. The heat capacity of solid inorganic substance is exactly equal to the heat capacity of the substance in the molten state
C. There is an increase in entropy, when a spontaneous change occurs in an isolated system
D. At absolute zero temperature, the heat capacity for many pure crystalline substances is zero
Answer : B

19. Pick out the correct statement.
A. The available energy in an isolated system for all irreversible (real) processes decreases
B. The efficiency of a Carnot engine increases, if the sink temperature is decreased
C. The reversible work for compression in non-flow process under isothermal condition is the change in Helmholtz free energy
D. All (A), (B) and (C)
Answer : D

20. In reactions involving solids and liquids (where change in volume is negligible), the heat of reaction at constant pressure as compared to that at constant volume is
A. More
B. Less
C. Same
D. Unpredictable; depends on the particular reaction
Answer : C

21. What is the value of Joule-Thomson co-efficient for an ideal gas?
A. +ve
B. -ve
C. 0
D. ?
Answer : C

22. Compressibility factor (i.e., the ratio of actual volume of gas to the volume predicted by ideal gas law) for all gases are
A. Always greater than one
B. Same at the same reduced temperature
C. Same at the same reduced pressure
D. Both (B) & (C)
Answer : D

23. Joule-Thomson co-efficient which is defined as, ? = (?T/?P)H = 1/Cp (?H/?T)P, changes sign at a temperature known as inversion temperature. The value of Joule-Thomson co-efficient at inversion temperature is
A. 0
B. ?
C. +ve
D. -ve
Answer : A

24. A refrigerator works on the principle of __________ law of thermodynamics.
A. Zeroth
B. First
C. Second
D. Third
Answer : C

25. An ideal gas is taken around the cycle ABCA as shown in P-V diagram below: The work done by the gas during the cycle is equal to

A. 12 P1V1
B. 6 P1 V1
C. 3 P1V1
D. P1 V1
Answer : C

26. The amount of heat required to decompose a compound into its elements is __________ the heat of formation of that compound from its elements.
A. Less than
B. More than
C. Same as
D. Not related to
Answer : C

27. Normal temperature and pressure (N.T.P.) corresponds to
A. 0°C and 760 mm Hg
B. 15°C and 760 mm Hg
C. 20°C and 760 mm Hg
D. 0°C and 1 kgf/cm²
Answer : C

28. 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

29. As the entropy of the universe is increasing, day by day, the work producing capacity of a heat engine is
A. Not changed
B. Decreasing
C. Increasing
D. Data sufficient, can't be predicted
Answer : B

30. The rate at which a substance reacts is proportional to its active mass and the rate of a chemical reaction is proportional to the product of active masses of the reacting substances. This is the
A. Lewis-Randall rule
B. Statement of Van't Hoff Equation
C. Le-Chatelier's principle
D. None of these
Answer : D

31. Internal energy of an element at 1 atm and 25° C is __________ kcal/kg.mole.
A. 0
B. 273
C. 25
D. None of these
Answer : A

32. Number of phases in a colloidal system is:
A. 1
B. 2
C. 3
D. 4
Answer : B

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

34. Work done is a
A. Property of the system
B. Path function
C. Point function
D. State description of a system
Answer : B

35. If the internal energy of an ideal gas decreases by the same amount as the work done by the system, then the
A. Process must be isobaric
B. Temperature must decrease
C. Process must be adiabatic
D. Both (B) and (C)
Answer : D

36. For a multi-component system, the term chemical potential is equivalent to the
A. Molal concentration difference
B. Molar free energy
C. Partial molar free energy
D. Molar free energy change
Answer : C

37. Partial molar free energy of an element A in solution is same as its
A. Chemical potential
B. Activity
C. Fugacity
D. Activity co-efficient
Answer : A

38. During a reversible isothermal expansion of an ideal gas, the entropy change is
A. +ve
B. 0
C. -ve
D. ?
Answer : A

39. The internal energy of an ideal gas is a function of its __________ only.
A. Molecular size
B. Volume
C. Pressure
D. Temperature
Answer : D

40. One ton of refrigeration capacity is equivalent to the heat removal rate of
A. 50 kcal/hr
B. 200 BTU/hr
C. 200 BTU/minute
D. 200 BTU/day
Answer : C

41. All gases except __________ shows a cooling effect during throttling process at atmospheric temperature and pressure.
A. Oxygen
B. Nitrogen
C. Air
D. Hydrogen
Answer : D

42. Pick out the wrong statement.
A. Surface tension of a substance vanishes at critical point, as there is no distinction between liquid and vapour phases at its critical point
B. Entropy of a system decreases with the evolution of heat
C. Change of internal energy is negative for exothermic reactions
D. The eccentric factor for all materials is always more than one
Answer : D

43. Specific/molar Gibbs free energy for a pure substance does not change during
A. Sublimation
B. Vaporisation
C. Melting
D. Either (A), (B) or (C)
Answer : D

44. The thermodynamic law, PV^y = constant, is not applicable in case of
A. Ideal compression of air
B. Free expansion of an ideal gas
C. Adiabatic expansion of steam in a turbine
D. Adiabatic compression of a perfect gas
Answer : B

45. Which of the following is a widely used refrigerant in vapour compression refrigeration system (using large centrifugal compressor)?
A. Freon
B. Liquid sulphur dioxide
C. Methyl chloride
D. Ammonia
Answer : A

46. At triple point (for one component system), vapour pressure of solid as compared to that of liquid will be
A. More
B. Less
C. Same
D. More or less; depending on the system
Answer : C

47. Which of the following is not an intensive property?
A. Chemical potential
B. Surface tension
C. Heat capacity
D. None of these
Answer : C

48. Pick out the wrong statement.
A. The conversion for a gas phase reaction increases with decrease in pressure, if there is an increase in volume accompanying the reaction
B. With increase in temperature, the equilibrium constant increases for an exothermic reaction
C. The equilibrium constant of a reaction depends upon temperature only
D. The conversion for a gas phase reaction increases with increase in pressure, if there is a decrease in volume accompanying the reaction
Answer : B

49. Change of heat content when one mole of compound is burnt in oxygen at constant pressure is called the
A. Calorific value
B. Heat of reaction
C. Heat of combustion
D. Heat of formation
Answer : C

50. The necessary condition for phase equilibrium in a multiphase system of N components is that the
A. Chemical potentials of a given component should be equal in all phases
B. Chemical potentials of all components should be same in a particular phase
C. Sum of the chemical potentials of any given component in all the phases should be the same
D. None of these
Answer : A