Chemical Engineering Thermodynamics - Study Mode
[#171] Compressibility factor of a gas is
Correct Answer
(A) Not a function of its pressure
Explanation
Solution: Compressibility factor of a real gas infect dependent on pressure at high pressure the molecules of the gas becomes so close that compressing this high pressure gas becomes more difficult than compressing the ideal gas the real gas becomes less compressible than ideal gas at high pressures.
[#172] In the equation, PV n = Constant, if the value of n = 0, then it represents a reversible __________ process.
Correct Answer
(A) Isobaric
Explanation
Solution: Pressure constant process is known as isobaric process.
[#173] As pressure approaches zero, the ratio of fugacity to pressure $$left( {frac{{ ext{f}}}{{ ext{P}}}}
ight)$$ xa0for a gas approaches
Correct Answer
(B) Unity
Explanation
Solution: As pressure approaches zero since gas approaches ideal behavior the ratio of fugacity and pressure becomes unity.
[#174] The theoretical minimum work required to separate one mole of a liquid mixture at 1 atm, containing 50 mole % each of n- heptane and n- octane into pure compounds each at 1 atm is
Correct Answer
(B) -RT ln 0.5
Explanation
Solution: Entropy of mixing is $$eqalign{
& = - Rsum {{X_i}ln {x_i}} cr
& = - Rleft[ {0.5,ln ,0.5 + 0.5,ln ,0.5}
ight] cr} $$ Since, work $$ = TDelta S = - RT,ln ,0.5.$$
[#175] When liquid and vapour phases of one component system are in equilibrium (at a given temperature and pressure), the molar free energy is
Correct Answer
(C) Same in both the phases
Explanation
Solution: If the liquid and vapor are pure, in that they consist of only one molecular component and no impurities, then the equilibrium state between the two phases is described by the following equations: P liq = p vap , T LIQ = T VAP , G LIQ = G VAP .