Chemical Engineering – Page 439

4381. 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.

4382. 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.

4383. Which of the following is a widely used refrigerant in vapour compression refrigeration system (using large centrifugal compressor)?

A. Freon

B. Liquid sulphur dioxide

C. Methyl chloride

D. Ammonia

✅ The correct answer is option A.

4384. Free energy

A. Decreases in all spontaneous (or irreversible) processes

B. Change during a spontaneous process has a negative value

C. Remains unchanged in reversible processes carried at constant temperature and pressure

D. All of the above

✅ The correct answer is option D.

4385. Work done in an adiabatic process between two states depends on the

A. Rate of heat transmission

B. Initial state only

C. End states only

D. None of these

✅ The correct answer is option C.

4386. 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.

4387. Duringthe phase transition, __________ changes.

A. Pressure

B. Volume

C. Temperature

D. All of the above

✅ The correct answer is option B.

4388. Absorption/evolution of heat during conversion of a substance from one allotropic form to another is termed as the heat of

A. Sublimation

B. Fusion

C. Transition

D. Vaporisation

✅ The correct answer is option C.

4389. One mole of nitrogen at 8 bar and 600 K is contained in a piston-cylinder arrangement. It is brought to 1 bar isothermally against a resisting pressure of 1 bar. The work done (in Joules) by the gas is

A. 30554

B. 10373

C. 4988.4

D. 4364.9

✅ The correct answer is option B.

4390. If heat contents of CH₄, C₂H₄ and C₃H₈ are -17.9, 12.5 and -24.8 kcal/mole respectively, than ΔH for the reaction CH₄(g) + C₂H₄(g) ⇋ C₃H₈(g) will be __________ Kcal.

A. -19.4

B. -30.2

C. 55.2

D. -55.2

✅ The correct answer is option A.