A. 0
B. ∞
C. 50
D. 100
✅ The correct answer is option B.
Thermodynamics MCQs
242. The molar excess Gibbs free energy, gE, for a binary liquid mixture at T and P is given by, (gE/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
✅ The correct answer is option A.
243. If two gases have same reduced temperature and reduced pressure, then they will have the same
A. Volume
B. Mass
C. Critical temperature
D. None of these
✅ The correct answer is option D.
244. Ideal gas law is applicable at
A. Low T, low P
B. High T, high P
C. Low T, high P
D. High T, low P
✅ The correct answer is option D.
245. Duringthe phase transition, __________ changes.
A. Pressure
B. Volume
C. Temperature
D. All of the above
✅ The correct answer is option B.
246. The extensive properties are
A. Volume, mass and number of moles
B. Free energy, entropy and enthalpy
C. Both A and B
D. None of these
✅ The correct answer is option C.
247. Pick out the undesirable property for a good refrigerant.
A. High thermal conductivity
B. Low freezing point
C. Large latent heat of vaporisation
D. High viscosity
✅ The correct answer is option D.
248. Fugacity co-efficient of a substance is the ratio of its fugacity to
A. Mole fraction
B. Activity
C. Pressure
D. Activity co-efficient
✅ The correct answer is option C.
249. The thermodynamic law, PVy = 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
✅ The correct answer is option B.
250. In a turbine, the fluid expands almost
A. Isothermally
B. Isobarically
C. Adiabatically
D. None of these
✅ The correct answer is option C.