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What is the correct answer?

4

The expression, ΔG = nRT. ln(P2/P1), gives the free energy change

A. With pressure changes at constant temperature

B. Under reversible isothermal volume change

C. During heating of an ideal gas

D. During cooling of an ideal gas

Correct Answer :

A. With pressure changes at constant temperature


Related Questions

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4

During the phase transition, __________ changes.

A. Pressure

B. Volume

C. Temperature

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

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4

The equation, (d loge PA/d loge xA) = (d loge PA/d loge xB) applicable to a binary solution of components. A and B in equilibrium with their vapors at constant temperature and pressure is called the __________ equation.

A. Van Laar

B. Margules

C. Gibbs-Duhem

D. Gibbs-Duhem-Margules

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4

Number of phases in a colloidal system is:

A. 1

B. 2

C. 3

D. 4

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4

In a reversible process

A. Tds = dE + dW

B. dE - dW = Tds

C. dW - dE = Tds

D. Tds - dW + dE >0

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4

In polytropic process (PVn = constant), if n = 1; it means a/an __________ process.

A. Adiabatic

B. Reversible

C. Isothermal

D. None of these

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4

Reduced pressure of a gas is the ratio of its

A. Pressure to critical pressure

B. Critical pressure to pressure

C. Pressure to pseudocritical pressure

D. Pseudocritical pressure to pressure

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4

Melting of ice exemplifies a/an

A. Adiabatic process

B. Endothermic reaction

C. Exothermic reaction

D. Process involving a chemical reaction

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4

The internal energy of an ideal gas does not change in a reversible __________ process.

A. Isothermal

B. Adiabatic

C. Isobaric

D. Isometric

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4

Pick out the wrong statement.

A. System (of partially miscible liquid pairs), in which the mutual solubility increases with rise in temperature, are said to possess an upper consolute temperature

B. Systems, in which the mutual solubility increases with decrease in temperature, are said to possess lower consolute temperature

C. Nicotine-water system shows both an upper as well as a lower consolute temperature, implying that they are partially miscible between these two limiting temperatures

D. None of these

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4

Claude gas liquefaction process employs cooling

A. At constant pressure

B. By throttling

C. By expansion in an engine

D. None of these

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4

The ratio of equilibrium constants (Kp2/Kp1) at two different temperatures is given by

A. (R/ΔH) (1/T1 - 1/T2)

B. (ΔH/R) (1/T1 - 1/T2)

C. (ΔH/R) (1/T2 - 1/T1)

D. (1/R) (1/T1 - 1/T2)

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4

A refrigeration cycle is a reversed heat engine. Which of the following has the maximum value of the co-efficient of performance (COP) for a given refrigeration effect?

A. Vapor compression cycle using expansion valve

B. Air refrigeration cycle

C. Vapor compression cycle using expansion engine

D. Carnot refrigeration cycle

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4

Compressibility factor for almost all the gases are approximately same at the same

A. Pressure and temperature

B. Reduced pressure and reduced temperature

C. Critical pressure and critical temperature

D. None of these

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4

When a system in equilibrium is subjected to a change in temperature, pressure or concentration, the equilibrium is displaced in a direction which tends to undo the effect of the change. This is called the

A. Le-Chatelier principle

B. Kopp's rule

C. Law of corresponding state

D. Arrhenius hypothesis

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4

A system is said to be isopiestic, if there is no __________ change.

A. Temperature

B. Pressure

C. Volume

D. None of these

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4

Pick out the wrong statement.

A. Minimum number of degree of freedom of a system is zero

B. Degree of freedom of a system containing a gaseous mixture of helium, carbon dioxide and hydrogen is 4

C. For a two phase system in equilibrium made up of four non-reacting chemical species, the number of degrees of freedom is 4

D. Enthalpy and internal energy change is zero during phase change processes like melting, vaporisation and sublimation

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4

The temperature at which a real gas obeys the ideal gas laws over a wide range of pressure is called the __________ temperature.

A. Critical

B. Boyle

C. Inversion

D. Reduced

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4

Pressure-enthalpy chart is useful in refrigeration. The change in internal energy of an ideal fluid used in ideal refrigeration cycle is

A. Positive

B. Negative

C. Zero

D. Infinity

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4

The standard state of a gas (at a given temperature) is the state in which fugacity is equal to

A. Unity

B. Activity

C. Both (A) & (B)

D. Neither (A) nor (B)

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4

For the reversible exothermic reaction, N2 + 3H2 2NH3, increase of pressure would

A. Shift the equilibrium towards right

B. Give higher yield of NH3

C. Both (B) and (C)

D. Neither (A) nor (B)

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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

In the reaction, represented by, 2SO2 + O2 2SO3; ΔH = - 42 kcal; the forward reaction will be favoured by

A. Low temperature

B. High pressure

C. Both (A) and (B)

D. Neither (A) nor (B)

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4

Equilibrium constant decreases as the temperature

A. Increases, for an exothermic reaction

B. Decreases, for an exothermic reaction

C. Increases, for an endothermic reaction

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

When liquid and vapour phases of one component system are in equilibrium (at a given temperature and pressure), the molar free energy is

A. More in vapour phase

B. More in liquid phase

C. Same in both the phases

D. Replaced by chemical potential which is more in vapour phase

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4

Clausius-Clapeyron equation is applicable to __________ equilibrium processes.

A. Solid-vapor

B. Solid-liquid

C. Liquid-vapor

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

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4

Which of the following is Virial equation of state?

A. (p + a/V2)(V - b) = nRT

B. PV = nRT

C. PV = A + B/V + C/V2 + D/V3 + ...

D. None of these

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4

The effect of changing the evaporator temperature on COP as compared to that of changing the condenser temperature (in vapour compression refrigeration system) is

A. Less pronounced

B. More pronounced

C. Equal

D. Data insufficient, can't be predicted

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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