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At 60° C, vapour pressure of methanol and water are 84.562 kPa and 19.953 kPa respectively. An aqueous solution of methanol at 60° C exerts a pressure of 39.223 kPa; the liquid phase and vapour phase mole fractions of methanol are 0.1686 and 0.5714 respectively. Activity co-efficient of methanol is

A. 1.572

B. 1.9398

C. 3.389

D. 4.238

Correct Answer :

A. 1.572


Related Questions

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4

Heat is added at constant pressure in an ideal __________ cycle.

A. Stirling

B. Brayton

C. Rankine

D. Both (B) and (C)

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4

When a gas is expanded from high pressure region to low pressure region; temperature change occurs. This phenomenon is related to the

A. Gibbs-Duhem equation

B. Gibbs-Helmholtz equation

C. Third law of thermodynamics

D. Joule-Thomson effect

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4

Gibbs phase rule finds application, when heat transfer occurs by

A. Conduction

B. Convection

C. Radiation

D. Condensation

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4

Which of the following is not an extensive property?

A. Free energy

B. Entropy

C. Refractive index

D. None of these

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4

What is the ratio of adiabatic compressibility to isothermal compressibility?

A. 1

B. < 1

C. > 1

D. >> 1

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4

Mollier chart is a __________ plot.

A. Pressure vs. enthalpy

B. Pressure vs. volume

C. Enthalpy vs. entropy

D. Temperature vs. entropy

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4

If the internal energy of an ideal gas decreases by the same amount as the work done by the system, then the

A. Process must be isobaric

B. Temperature must decrease

C. Process must be adiabatic

D. Both (B) and (C)

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4

The first law of thermodynamics is a restatement of the law of conservation of

A. Mass

B. Energy

C. Momentum

D. None of these

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4

Which of the following is not an intensive property?

A. Volume

B. Density

C. Temperature

D. Pressure

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4

Requisites of a reversible process is that the

A. System and surroundings pressure be equal

B. Friction in the system should be absent

C. System and surroundings temperature be equal

D. None of these

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4

The acentric factor of a materical, 'ω', is defined as ω = -log10(Prsat)Tr-1 = 0.7, where, Prsat = reduced vapor pressure, Tr = reduced temperature. The value of acentric factor is always

A. > 2

B. < 1

C. > 1

D. < 3

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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

The change in __________ is equal to the reversible work for compression in steady state flow process under isothermal condition.

A. Internal energy

B. Enthalpy

C. Gibbs free energy

D. Helmholtz free energy

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4

For an ideal gas, the internal energy depends upon its __________ only.

A. Molecular size

B. Temperature

C. Volume

D. Pressure

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4

For an ideal gas, the chemical potential is given by

A. RT d ln P

B. R d ln P

C. R d ln f

D. None of these

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4

In reactions involving solids and liquids (where change in volume is negligible), the heat of reaction at constant pressure as compared to that at constant volume is

A. More

B. Less

C. Same

D. Unpredictable; depends on the particular reaction

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4

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 (A), (B) and (C)

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4

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

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4

The number of degrees of freedom at the triple point of water is

A. 0

B. 1

C. 2

D. 3

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4

For the gaseous phase chemical reaction, C2H4(g) + H2O(g) ↔ C2H5OH(g), the equilibrium conversion does not depend on the

A. Steam to ethylene ratio

B. Temperature

C. Pressure

D. None of these

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4

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

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4

In a homogeneous solution, the fugacity of a component depends upon the

A. Pressure

B. Composition

C. Temperature

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

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4

__________ functions are exemplified by heat and work.

A. Path

B. Point

C. State

D. None of these

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4

Which of the following is not a reversible process?

A. Expansion of an ideal gas against constant pressure

B. Atmospheric pressure vaporisation of water at 100°C

C. Solution of NaCl in water at 50°C

D. None of these

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4

Consider the reaction, C + O2 CO2; ΔH = - 94 kcal. What will be the value of ΔH for the reaction CO2 → C + O2?

A. -94 kcal

B. +94 kcal

C. > 94 kcal

D. < -94 kcal

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4

Pick out the Clausius-Clapeyron equation from the following:

A. dP/dT = ΔH/TΔV

B. ln P = - (ΔH/RT) + constant

C. ΔF = ΔH + T [∂(ΔF)/∂T]P

D. None of these

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4

Pick out the correct statement.

A. Entropy and enthalpy are path functions

B. In a closed system, the energy can be exchanged with the surrounding, while matter cannot be exchanged

C. All the natural processes are reversible in nature

D. Work is a state function

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4

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

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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

High __________ is an undesirable property for a good refrigerant.

A. Specific heat

B. Latent heat of vaporisation

C. Viscosity

D. Specific vapor volume