114. The second law of thermodynamics states that

A. The energy change of a system undergoing any reversible process is zero
B. It is not possible to transfer heat from a lower temperature to a higher temperature
C. The total energy of system and surrounding remains the same
D. None of the above
✅ The correct answer is option D.

118. A reasonably general expression for vapour-liquid phase equilibrium at low to moderate pressure is Φi yi P = Yi xi fi° where, Φ is a vapor fugacity component, Yi is the liquid activity co-efficient and fi° is the fugacity of the pure component i. the Ki value (Yi = Ki xi) is therefore, in general a function of

A. Temperature only
B. Temperature and pressure only
C. Temperature, pressure and liquid composition xi only
D. Temperature, pressure, liquid composition xi and vapour composition yi
✅ The correct answer is option C.

120. A two stage compressor is used to compress an ideal gas. The gas is cooled to the initial temperature after each stage. The intermediate pressure for the minimum total work requirement should be equal to the __________ mean of P₁ and P₂.(where, P₁ and P₂ are initial and final pressures respectively)

A. Logarithmic
B. Arithmetic
C. Geometric
D. Harmonic
✅ The correct answer is option C.