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4

The theoretical minimum work required to separate one mole of a liquid mixture at 1 atm, containing 50 mole % each of n- heptane and noctane into pure compounds each at 1 atm is

A. -2 RT ln 0.5

B. -RT ln 0.5

C. 0.5 RT

D. 2 RT

Correct Answer :

B. -RT ln 0.5


Related Questions

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4

The amount of heat required to decompose a compound into its elements is __________ the heat of formation of that compound from its elements.

A. Less than

B. More than

C. Same as

D. Not related to

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4

The temperature at which both liquid and gas phases are identical, is called the __________ point.

A. Critical

B. Triple

C. Freezing

D. Boiling

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4

Heat pump

A. Accomplishes only space heating in winter

B. Accomplishes only space cooling in summer

C. Accomplishes both (A) and (B)

D. Works on Carnot cycle

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4

Any substance above its critical temperature exists as

A. Saturated vapour

B. Solid

C. Gas

D. Liquid

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4

For equilibrium process (i.e. reversible) in an isolated system

A. ds = 0

B. ds < 0

C. ds > 0

D. ds = Constant

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4

For water at 300°C, it has a vapour pressure 8592.7 kPa and fugacity 6738.9 kPa Under these conditions, one mole of water in liquid phase has a volume of 25.28 cm3 and that in vapour phase in 391.1 cm3.Fugacity of water (in kPa) at 9000 kPa will be

A. 6738.9

B. 6753.5

C. 7058.3

D. 9000

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4

Which of the following is not a common refrigerant?

A. Freon-12

B. Ethylene

C. Ammonia

D. Carbon dioxide

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4

Pick out the wrong statement pertaining to the decomposition of PCl5 represented by, PCl5 PCl3 + Cl2.Degree of dissociation of PCl5 will

A. Decrease on addition of Cl2

B. Increase on addition of an inert gas at constant pressure

C. Decrease on increasing the pressure of the system

D. None of these

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4

Activity co-efficient is a measure of the

A. Departure from ideal solution behaviour

B. Departure of gas phase from ideal gas law

C. Vapour pressure of liquid

D. None of these

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4

Clapeyron Equation deals with the

A. Rate of change of vapour pressure with temperature

B. Effect of an inert gas on vapour pressure

C. Calculation of ΔF for spontaneous phase change

D. Temperature dependence of heat of phase transition

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4

Fundamental principle of refrigeration is based on the __________ law of thermodynamics.

A. Zeroth

B. First

C. Second

D. Third

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4

A thermodynamic system is taken from state A to B along ACB and is brought back to A along BDA as shown below in the P-V diagram. The net work done during the complete cycle is given by the area covered by

A. P1ACBP2P1

B. ACBB1A1A

C. ACBDA

D. ADBB1A1A

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4

Which of the following is true for Virial equation of state?

A. Virial co-efficients are universal constants

B. Virial co-efficients 'B' represents three body interactions

C. Virial co-efficients are function of temperature only

D. For some gases, Virial equations and ideal gas equations are the same

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4

Fugacity is a measure of the

A. Escaping tendencies of the same substance in different phases of a system

B. Relative volatility of a mixture of two miscible liquids

C. Behaviour of ideal gases

D. None of these

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4

The ammonia synthesis reaction represented by N2 + 3H2 2NH3; ΔH = - 22.4 kcal, is

A. Endothermic

B. Exothermic

C. Isothermal

D. Adiabatic

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4

A Carnot cycle consists of the following steps:

A. Two isothermal and two isentropic

B. Two isobaric and two isothermal

C. Two isochoric and two isobaric

D. Two isothermals and two isochoric

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4

For a reversible process involving only pressure-volume work

A. (dF)T, p < 0

B. (dF)T, p > 0

C. (dF)T, p = 0

D. (dA)T, v < 0

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4

Which of the following equations is obtained on combining 1st and 2nd law of thermodynamics, for a system of constant mass?

A. dE = Tds - PdV

B. dQ = CvdT + PdV

C. dQ = CpdT + Vdp

D. Tds = dE - PdV

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4

A solute distributes itself between two nonmiscible solvents in contact with each other in such a way that, at a constant temperature, the ratio of its concentrations in two layers is constant, irrespective of its total amount. This is

A. The distribution law

B. Followed from Margules equation

C. A corollary of Henry's law

D. None of these

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4

Which of the following decreases with increase in pressure?

A. Melting point of ice

B. Melting point of wax

C. Boiling point of liquids

D. None of these

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4

Compressibility factor-reduced pressure plot on reduced co-ordinates facilitates

A. Use of only one graph for all gases

B. Covering of wide range

C. Easier plotting

D. More accurate plotting

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4

At normal boiling point, molar entropy of vaporisation is __________ Joule/K°.mole.

A. 72

B. 92

C. 142

D. 192

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4

A closed system is cooled reversibly from 100°C to 50°C. If no work is done on the system

A. its internal energy (U) decreases and its entropy (S) increases

B. U and S both decreases

C. U decreases but S is constant

D. U is constant but S decreases

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4

Vapour which is at a pressure smaller than the saturation pressure for the temperature involved is called a __________ vapour.

A. Superheated

B. Desuperheated

C. Non-condensable

D. None of these

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4

The standard Gibbs free energy change of a reaction depends on the equilibrium

A. Pressure

B. Temperature

C. Composition

D. All (A), (B) and (C)

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4

The Maxwell relation derived from the differential expression for the Helmholtz free energy (dA) is

A. (∂T/∂V)S = - (∂P/∂S)V

B. (∂S/∂P)T = - (∂V/∂T)P

C. (∂V/∂S)P = (∂T/∂P)S

D. (∂S/∂V)T = (∂P/∂T)V

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4

A change in state involving a decrease in entropy can be spontaneous, only if

A. It is exothermic

B. It is isenthalpic

C. It takes place isothermally

D. It takes place at constant volume

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4

If the heat of solution of an ideal gas in a liquid is negative, then its solubility at a given partial pressure varies with the temperature as

A. Solubility increases as temperature increases

B. Solubility increases as temperature decreases

C. Solubility is independent of temperature

D. Solubility increases or decreases with temperature depending on the Gibbs free energy change of solution

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4

For a real gas, the chemical potential is given by

A. RT d ln P

B. RT d ln f

C. R d ln f

D. None of these

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4

Which of the following is affected by the temperature?

A. Fugacity

B. Activity co-efficient

C. Free energy

D. All (A), (B) & (C)