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 12 of 30
- A. Both A. & B
- B. Activity
- C. Unity
- D. Neither A. nor B
Explanation: A standard state is the reference state for which the normalized fugacity and activity are taken as unity.
Correct answer: Both A. & B- A. 100,000 kW
- B. 160,000 kW
- C. 200,000 kW
- D. 320,000 kW
Explanation: The Carnot efficiency is 1 - 300/800 = 0.625, so the engine efficiency is 0.5(0.625) = 0.3125.
Correct answer: 320,000 kW- A. Isobaric
- B. Adiabatic
- C. Both B. & C.
- D. Isenthalpic
Explanation: In the Joule-Thomson experiment, the porous-plug process is steady-flow, adiabatic, and has negligible changes in kinetic and potential…
Correct answer: Both B. & C.- A. 0
- B. 1
- C. 2
- D. 3
Explanation: For a nonreacting two-component gaseous mixture in one phase, Gibbs phase rule gives F = C - P + 2 = 2 - 1 + 2 = 3.
Correct answer: 3- A. Minus infinity
- B. Infinity
- C. Zero
- D. None of these
Explanation: For a pure fluid at constant temperature, the chemical potential or molar Gibbs energy contains the term RT ln f.
Correct answer: Minus infinity226. The quantitative effect of temperature on chemical equilibrium is given by the____________________?
- A. Le-Chatelier's principle
- B. Van't-Hoff equation
- C. Arrhenius equation
- D. None of these
Explanation: The van’t Hoff equation gives the quantitative relation between the equilibrium constant and temperature, involving the reaction enthalpy.
Correct answer: Van't-Hoff equation- A. Endothermic
- B. Isothermal
- C. Exothermic
- D. Adiabatic
Explanation: A negative enthalpy change means heat is released by the reaction, so ammonia synthesis is exothermic.
Correct answer: Exothermic- A. ∞
- B. 0
- C. Maximum
- D. Minimum
Explanation: At constant temperature and pressure, a system reaches equilibrium when its Gibbs free energy is at a minimum.
Correct answer: Minimum- A. +94 kcal
- B. -94 kcal
- C. > 94 kcal
- D. < -94 kcal
Explanation: Reversing a reaction reverses the sign of its enthalpy change, so decomposition of CO₂ requires +94 kcal.
Correct answer: +94 kcal- A. Solubility increases as temperature increases
- B. of solution
- C. Solubility is independent of temperature
- D. Solubility increases or decreases with temperature depending on the Gibbs free energy change
- E. Solubility increases as temperature decreases
Explanation: A negative heat of solution indicates exothermic dissolution, so increasing temperature reduces gas solubility at fixed partial pressure.
Correct answer: Solubility increases as temperature decreases- A. Temperature changes only
- B. Orderly behaviour
- C. Disorder
- D. None of these
Explanation: Entropy is commonly interpreted as the measure of molecular disorder or the number of accessible microscopic arrangements.
Correct answer: Disorder- A. Kinematic viscosity
- B. Work
- C. Temperature
- D. None of these
Explanation: COP is a ratio of refrigeration effect to work input, so it is dimensionless.
Correct answer: None of these- A. Separating
- B. Bomb
- C. Bucket
- D. Throttling
Explanation: Separating, throttling, and bucket calorimeters are used to determine steam dryness fraction.
Correct answer: Bomb- A. Equal to its density
- B. Proportional to pressure
- C. The reciprocal of its density
- D. None of these
Explanation: Specific volume is volume per unit mass, while density is mass per unit volume, so they are reciprocals: v = 1/ρ.
Correct answer: The reciprocal of its density- A. Freezing
- B. Boyle
- C. Boiling
- D. Triple
Explanation: The triple point is the unique temperature and pressure at which solid, liquid, and vapour phases coexist in equilibrium.
Correct answer: Triple- A. Steam engine
- B. Carnot engine
- C. Diesel engine
- D. Otto engine
Explanation: A practical steam engine generally has the lowest thermal efficiency because much heat is rejected and its expansion is less efficient…
Correct answer: Steam engine- A. Low pressure and high temperature
- B. Low pressure and low temperature
- C. High pressure and low temperature
- D. High pressure and high temperature
Explanation: Le Chatelier's principle gives low pressure when dissolution causes an increase in volume, while liberation of heat is favoured by…
Correct answer: Low pressure and low temperature- A. Fusion
- B. Vaporisation
- C. None of these
- D. Transition
Explanation: The heat absorbed or released when a substance changes between two allotropes is called the heat of transition.
Correct answer: Transition- A. Stirling
- B. Brayton
- C. Rankine
- D. None of these
Explanation: The Stirling cycle has two isothermal processes, including isothermal heat addition, and two constant-volume regenerative processes.
Correct answer: Stirling- A. Kirchoff's
- B. Hess's
- C. Lavoisier and Laplace
- D. None of these
Explanation: Hess's law states that the enthalpy change of a reaction depends only on the initial and final states, not on the path or number of…
Correct answer: Hess's