1. Entropy change of the reaction, H₂O(liquid) H₂O(gas), is termed as the enthalpy of
A. Solution
B. Vaporisation
C. Formation
D. Formation
✅ The correct answer is option B.
Thermodynamics MCQs
2. Efficiency of a heat engine working on Carnot cycle between two temperature levels depends upon the
A. Two temperatures only
B. Pressure of working fluid
C. Mass of the working fluid
D. Mass and pressure both of the working fluid
✅ The correct answer is option A.
3. The expression for the work done for a reversible polytropic process can be used to obtain the expression for work done for all processes, except reversible __________ process.
A. Isobaric
B. Isothermal
C. Adiabatic
D. None of these
✅ The correct answer is option B.
4. For a spontaneous process, free energy
A. Is zero
B. Increases
C. Decreases whereas the entropy increases
D. And entropy both decrease
✅ The correct answer is option C.
5. The third law of thermodynamics states that the
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 behave similarly
D. None of these
✅ The correct answer is option A.
6. The Carnot co-efficient of performance (COP) of a domestic air conditioner compared to a household refrigerator is
A. Less
B. More
C. Same
D. Dependent on climatic conditions
✅ The correct answer is option A.
7. When pressure is applied on the system, ice ⟷ water, then
A. Equilibrium can not be established
B. More ice will be formed
C. More water will be formed
D. Evaporation of water will take place
✅ The correct answer is option C.
8. Gibbs free energy of a pure fluid approaches __________ as the pressure tends to zero at constant temperature.
A. Infinity
B. Minus infinity
C. Zero
D. None of these
✅ The correct answer is option B.
9. The enthalpy change when ammonia gas is dissolved in water is called the heat of
A. Solution
B. Formation
C. Dilution
D. Combustion
✅ The correct answer is option A.
10. During a reversible isothermal expansion of an ideal gas, the entropy change is
A. +ve
B. 0
C. -ve
D. ∞
✅ The correct answer is option A.