Free Chemical Engineering Thermodynamics MCQs with Answers
598 Chemical Engineering Thermodynamics MCQs from Chemical Engineering, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
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598 questions · page 22 of 30
- A. Pressure remains constant
- B. Pressure is increased
- C. None of these
- D. Temperature remains constant
Explanation: In adiabatic expansion, the gas generally does work without receiving heat, so its temperature and pressure decrease.
Correct answer: None of these- A. None of these
- B. Representing actual behaviour of ideal gases
- C. The study of chemical equilibria involving gases at atmospheric pressure
- D. Representing actual behaviour of real gases
Explanation: Fugacity is an effective pressure introduced to represent the escaping tendency of a real fluid, especially when it departs from ideal-gas…
Correct answer: Representing actual behaviour of real gases- A. A perfect
- B. Any
- C. An easily liquefiable
- D. A real
Explanation: For a perfect gas, enthalpy depends only on temperature, and at constant pressure the temperature remains constant for a fixed amount and…
Correct answer: A perfect- A. Pressure
- B. Composition
- C. Temperature
- D. All A, B. and C
Explanation: For a specified reaction and standard states, the standard Gibbs free energy change is principally a function of temperature, related by…
Correct answer: Temperature- A. A . x22
- B. Ax1
- C. Ax2
- D. Ax12
Explanation: The activity coefficient follows from differentiating the total excess Gibbs energy with respect to the amount of component 1.
Correct answer: A . x22- A. High T, low P
- B. High T, high P
- C. Low T, high P
- D. Low T, low P
Explanation: Ideal-gas behaviour is approached at high temperature and low pressure because molecular attractions and molecular volume become…
Correct answer: High T, low P- A. Indeterminate
- B. Zero
- C. Negative
- D. None of these
Explanation: In free expansion, the gas expands into a vacuum, so the external resisting pressure is zero.
Correct answer: Zero- A. Decrease in velocity
- B. Decrease in temperature
- C. Energy spent in doing work
- D. Decrease in kinetic energy
Explanation: For adiabatic expansion, no heat enters the gas, so the energy required for expansion work comes from its internal energy.
Correct answer: Energy spent in doing work- A. Two isothermals and two isochoric
- B. Two isobaric and two isothermal
- C. Two isochoric and two isobaric
- D. Two isothermal and two isentropic
Explanation: A reversible Carnot cycle has two constant-temperature heat-transfer processes and two reversible adiabatic processes.
Correct answer: Two isothermal and two isentropic- A. Lewis-Randall rule
- B. None of these
- C. Le-Chatelier's principle
- D. Statement of Van't Hoff Equation
Explanation: The statement describes the law of mass action, which says that reaction rate depends on the product of the reactants' active masses.
Correct answer: None of these- A. Throttling
- B. Following a constant pressure cycle
- C. Expansion in an engine
- D. None of these
Explanation: Claude's process obtains cooling mainly through expansion in an engine, where the gas performs work and its temperature falls.
Correct answer: Expansion in an engine- A. Circle
- B. Rhombus
- C. Trapezoid
- D. Rectangle
Explanation: On a T-S diagram, the two isothermal Carnot processes are horizontal lines and the two isentropic processes are vertical lines.
Correct answer: Rectangle- A. Non-polar
- B. Polar
- C. Both A. & B
- D. Neither A. nor B
Explanation: The Kistyakowsky correlation is used for the entropy or Trouton ratio of non-polar liquids, for which intermolecular association is…
Correct answer: Non-polar- A. 349
- B. 651
- C. 667
- D. 1000
Explanation: Maximum work is obtained from a reversible Carnot cycle: W = Qh(1 − Tc/Th) = 1000[1 − 373/573] ≈ 349 J.
Correct answer: 349- A. Enthalpy does not remain constant
- B. Entire apparatus is exposed to surroundings
- C. None of these
- D. Temperature remains constant
Explanation: A porous-plug experiment is a throttling process, and for steady flow with negligible heat transfer, work, and kinetic-energy changes…
Correct answer: None of these- A. All a, b & c
- B. Pressure
- C. Temperature
- D. Volume
Explanation: During a usual first-order phase transition, the specific volume changes because the two phases have different densities.
Correct answer: Volume- A. (∂E/∂T)V
- B. (∂E/∂V)T
- C. (∂E/∂P)V
- D. (∂V/∂T)P
Explanation: By definition, heat capacity at constant volume is the change in internal energy with temperature while volume is fixed: Cv = (∂E/∂T)V.
Correct answer: (∂E/∂T)V- A. P1ACBP2P1
- B. ACBDA
- C. ACBB1A1A
- D. ADBB1A1A
Explanation: For a complete cycle, the net work equals the closed area on the P-V diagram, namely the region enclosed by the forward path ACB and…
Correct answer: ACBDA- A. 0.5
- B. 1
- C. 3.5
- D. 9.05
Explanation: Average seawater contains about 35 grams of dissolved salts per litre, corresponding to approximately 3.5% by mass.
Correct answer: 3.5- A. [∂(G/T)/∂T] = - (H/T2)
- B. [∂(A/T)/∂T]V = - E/T2
- C. Neither A. nor B.
- D. Both A. and B.
Explanation: Differentiating G/T at constant pressure gives −H/T², while differentiating A/T at constant volume gives −E/T².
Correct answer: Both A. and B.