A. (atm)Δx, when Δx is negative
B. (atm)Δx, when Δx is positive
C. Dimensionless, when Δx = 0
D. (atm)Δx2, when Δx > 0
✅ The correct answer is option D.
Thermodynamics MCQs
132. Throttling process is a/an __________ process.
A. Reversible and isothermal
B. Irreversible and constant enthalpy
C. Reversible and constant entropy
D. Reversible and constant enthalpy
✅ The correct answer is option B.
133. The internal energy of a gas obeying P (V – b) RT (where, b is a positive constant and has a constant Cv), depends upon its
A. Pressure
B. Volume
C. Temperature
D. All of the above
✅ The correct answer is option C.
134. Which is not a refrigerant?
A. SO₂
B. NH₃
C. CCl₂F₂
D. C₂H₄Cl₂
✅ The correct answer is option D.
135. Critical solution temperature (or the con-solute temperature) for partially miscible liquids (e.g., phenol-water) is the minimum temperature at which
A. A homogeneous solution (say of phenol water) is formed
B. Mutual solubility of the two liquids shows a decreasing trend
C. Two liquids are completely separated into two layers
D. None of these
✅ The correct answer is option A.
136. Co-efficient of Performance (COP) of a refrigerator is the ratio of the
A. Work required to refrigeration obtained
B. Refrigeration obtained to the work required
C. Lower to higher temperature
D. Higher to lower temperature
✅ The correct answer is option B.
137. Co-efficient of performance for a reversed Carnot cycle working between temperatures T₁ and T₂ (T₁ > T₂) is
A. T₂/(T₁ – T₂)
B. T₁/(T₁ – T₂)
C. (T₁ – T₂)/T₁
D. (T₁ – T₂)/T₂
✅ The correct answer is option A.
138. Specific __________ does not change during a phase change (e.g. sublimation, melting, vaporisation etc.).
A. Entropy
B. Internal energy
C. Enthalpy
D. Gibbs free energy
✅ The correct answer is option D.
139. Kopp’s rule is used to calculate the heat capacity of
A. Solids
B. Liquids
C. Gases
D. All of the above
✅ The correct answer is option A.
140. Free energy changes for two reaction mechanism ‘X’ and ‘Y are respectively – 15 and – 5 units. It implies that X is
A. Slower than Y
B. Faster than Y
C. Three times slower than Y
D. Three times faster than Y
✅ The correct answer is option B.