Q.1

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

  • dE = Tds - PdV
  • dQ = CvdT + PdV
  • dQ = CpdT + Vdp
  • Tds = dE - PdV
Q.2

Molar heat capacity of water in equilibrium with ice at constant pressure is __________ Kcal/kg mole . °K

  • 0
  • 50
  • 100
Q.3

In case of an __________ process, the temperature of the system increases.

  • isothermal compression
  • isothermal expansion
  • adiabatic expansion
  • adiabatic compression
Q.4

PVy = constant, holds good for an isentropic process, which is

  • reversible and isothermal.
  • isothermal and irreversible.
  • reversible and adiabatic.
  • adiabatic and irreversible.
Q.5

The adiabatic throttling process of a perfect gas is one of constant enthalpy

  • in which there is a temperature drop.
  • which is exemplified by a non-steady flow expansion.
  • which can be performed in a pipe with a constriction.
  • in which there is an increase in temperature.
Q.6

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

  • positive
  • negative
  • zero
  • infinity
Q.7

Degree of freedom of the system ice-water-vapour will be

  • 0
  • 1
  • 2
  • 3
Q.8

What happens in a reversible adiabatic expansion process ?

  • Heating takes place.
  • Cooling takes place.
  • Pressure is constant.
  • Temperature is constant.
Q.9

A gas can be liquified by pressure alone only, when its temperature is __________ its critical temperature.

  • less than
  • more than
  • equal to or higher than
  • less than or equal to
Q.10

Thermal efficiency of a Carnot engine can approach 100%, only when the temperature of the

  • cold reservoir approaches zero.
  • hot reservoir approaches infinity.
  • either (a) or (b).
  • neither (a) nor (b).
Q.11

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

  • unity
  • activity
  • both (a) & (b)
  • neither (a) nor (b)
Q.12

Fugacity co-efficient of a substance is the ratio of its fugacity to

  • mole fraction
  • activity
  • pressure
  • activity co-efficient
Q.13

For spontaneous changes in an isolated system (S = entropy)

  • ds = 0
  • ds <0
  • ds > 0
  • ds = Constant
Q.14

First law of thermodynamics deals with the

  • direction of energy transfer.
  • reversible processes only.
  • irreversible processes only.
  • none of these.
Q.15

A system in which there is exchange of energy but not of mass, is called a/an __________ system.

  • isolated
  • open
  • insulated
  • closed
Q.16

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

  • molecular size
  • temperature
  • volume
  • pressure
Q.17

Cp of a gas at its critical temperature and pressure

  • becomes zero.
  • becomes infinity.
  • equals 1 kcal/kmol °K.
  • equals 0.24 kcal/kmol °K.
Q.18

The variation of heat of reaction with temperature at constant pressure is given by the __________ law.

  • Kelvin's
  • Antonie's
  • Kirchoffs
  • none of these
Q.19

Which of the following behaves most closely like an ideal gas ?

  • He
  • N2
  • O2
  • H2
Q.20

The point at which all the three (solid, liquid and gas) phases co-exist, is known as the __________ point.

  • freezing
  • triple
  • boiling
  • Boyle
Q.21

In an ideal gas mixture, fugacity of a species is equal to its

  • vapor pressure
  • partial pressure
  • chemical potential
  • none of these
Q.22

Trouton's ratio is given by (where λb, = molal heat of vaporisation of a substance at its normal boiling point, kcal/kmol Tb = normal boiling point, °K )

  • λb/Tb
  • Tbb
  • λb/Tb
  • Tbb
Q.23

What is the degree of freedom for a system comprising liquid water equilibrium with its vapour ?

  • 0
  • 1
  • 2
  • 3
Q.24

At absolute zero temperature, the __________ of the gas is zero.

  • pressure
  • volume
  • mass
  • none of these
Q.25

Melting of wax is accompanied with __________ in entropy.

  • increase
  • decrease
  • no change
  • none of these
Q.26

Helmholtz free energy (A) is defined as

  • A = H - TS
  • A = E - TS
  • A = H + TS
  • none of these
Q.27

As pressure approaches zero, the ratio of fugacity to pressure (f/P) for a gas approaches

  • zero
  • unity
  • infinity
  • an indeterminate value
Q.28

Lenz's law results from the law of conservation of

  • mass
  • momentum
  • energy
  • none of these
Q.29

As pressure approaches zero, the ratio of fugacity to pressure (f/P) for a gas approaches

  • zero
  • unity
  • infinity
  • an indeterminate value
Q.30

For a constant volume process __________ by the system is used only to increase the internal energy.

  • heat absorbed
  • work done
  • both (a) & (b)
  • neither (a) nor (b)
Q.31

When a system is in equilibrium for all possible processes, the differential or finite change of entropy is

  • < 0
  • > 0
  • = 0
  • none of these
Q.32

Which of the following equations is used for the prediction of activity co-efficient from experiments ?

  • Van Laar equation
  • Margules equation
  • Wilson's equation
  • all (a), (b) and (c)
Q.33

For spontaneous changes in an isolated system (S = entropy)

  • ds = 0
  • ds <0
  • ds > 0
  • ds = Constant
Q.34

Trouton's ratio is given by (where λb, = molal heat of vaporisation of a substance at its normal boiling point, kcal/kmol Tb = normal boiling point, °K )

  • λb/Tb
  • Tbb
  • λb/Tb
  • Tbb
Q.35

First law of thermodynamics deals with the

  • direction of energy transfer.
  • reversible processes only.
  • irreversible processes only.
  • none of these.
Q.36

Work done in case of free expansion is

  • indeterminate
  • zero
  • negative
  • none of these
Q.37

For any system, what is the minimum number of degrees of freedom?

  • 1
  • 0
  • 2
  • 3
Q.38

A system is said to be at equilibrium, if the entropy of the system has reached __________ value.

  • minimum
  • zero
  • maximum
  • none of these
Q.39

At a given temperature, the volume of a gas dissolved in a solvent __________ with increase in pressure.

  • increases
  • decreases
  • remains unchanged
  • may increase or decrease; depends on the gas
Q.40

Chemical potential (an intensive property) of a substance is a force that drives the chemical system to equilibrium and is equal to its partial molar properties. The reatio of chemical potential to free energy of a pure substance at oconstant temperature and pressure is

  • 0
  • 1
  • none of these
Q.41

AtC, vapour pressure of methanol and water are 84.kPa and 19.kPa respectively. An aqueous solution of methanol atC exerts a pressure of 39.kPa; the liquid phase and vapour phase mole fractions of methanol are 0.and 0.respectively. Activity co-efficient of methanol is

  • 1.572
  • 1.9398
  • 3.389
  • 4.238
Q.42

In the equation, PVn = constant, if the value of n = ± ∞, then it represents a reversible __________ process.

  • adiabatic
  • isometric
  • isentropic
  • isothermal
Q.43

Third law of thermodynamics is helpful in

  • prediction of the extent of a chemical reaction.
  • calculating absolute entropies of substances at different temperature.
  • evaluating entropy changes of chemical reaction.
  • both (b) and (c)
Q.44

Entropy of a substance remains constant during a/an __________ change.

  • reversible isothermal
  • irreversible isothermal
  • reversible adiabatic
  • none of these
Q.45

Entropy change in case of reversible adiabatic process is

  • minimum
  • zero
  • maximum
  • indeterminate
Q.46

Which is an example of closed system ?

  • Air compressor
  • Lquid cooling system of an automobile
  • Boiler
  • None of these
Q.47

Heat evolved/absorbed during conversion of a substance from one allotropic form to another is termed as the heat of

  • fusion
  • vaporisation
  • transition
  • none of these
Q.48

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

  • use of only one graph for all gases.
  • covering of wide range.
  • easier plotting.
  • more accurate plotting.
Q.49

Which of the following behaves most closely like an ideal gas ?

  • He
  • N2
  • O2
  • H2
Q.50

During adiabatic expansion of gas

  • pressure remains constant.
  • pressure is increased.
  • temperature remains constant.
  • none of these.
0 h : 0 m : 1 s