Q.1

The change in Gibbs freee energy for vaporisation of a pure substance is

  • positive
  • negative
  • zero
  • may be positive or negative
Q.2

In case of a close thermodynamic system, there is __________ across the boundaries.

  • no heat and mass transfer
  • no mass transfer but heat transfer
  • mass and energy transfer
  • none of these
Q.3

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

  • solubility increases as temperature increases.
  • solubility increases as temperature decreases.
  • solubility is independent of temperature.
  • solubility increases or decreases with temperature depending on the Gibbs free energy change of solution.
Q.4

If we increase the pressure on a substance (which is at its triple point), then the triple point

  • increases
  • decreases
  • remains unchanged
  • may increase or decrease ; depends on the substance
Q.5

Number of phases in a colloidal system are

  • 1
  • 2
  • 3
  • 4
Q.6

For a constant volume process

  • dE = CpdT
  • dE = CvdT
  • dQ = dE + pdV
  • dW = pdV
Q.7

Refrigeration cycle

  • violates second law of thermodynamics.
  • involves transfer of heat from low temperature to high temperature.
  • both (a) and (b).
  • neither (a) nor (b).
Q.8

At equilibrium condition, the chemical potential of a material in different phases in contact with each other is equal. The chemical potential for a real gas (μ) is given by(where, μ = standard chemical potential at unit fugacity (f° = 1 atm.) and the gas behaves ideally.)

  • μ° + RT ln f
  • μ°+ R lnf
  • μ° + T lnf
  • μ° + R/T lnf
Q.9

y = specific heat ratio of an ideal gas is equal to

  • Cp/Cv
  • Cp/(CP-R)
  • 1 + (R/CV)
  • all (a), (b) and (c)
Q.10

Joule-Thomson co-efficient depends on the

  • pressure.
  • temperature.
  • both (a) & (b).
  • neither (a) nor (b).
Q.11

With increase in compression ratio, the efficiency of the otto engine

  • increases
  • decreases
  • remains constant
  • increases linearly
Q.12

For an ideal gas, the activity co-efficient is

  • directly proportional to pressure.
  • inversely proportional to pressure.
  • unity at all pressures.
  • none of these.
Q.13

In case of vapour compression refrigeration system, elevating the evaporator temperature (keeping the condenser temperature constant) results in

  • enhanced COP.
  • decreased COP.
  • no change in the value of COP.
  • increased or decreased COP ; depending upon the type of refrigerant.
Q.14

During a reversible isothermal expansion of an ideal gas, the entropy change is

  • +ve
  • 0
  • -ve
  • ∞
Q.15

In case of a reversible process (following pvn = constant), work obtained for trebling the volume (v1 = 1 m3 and v2 3 m3 ) is max imum, when the value of 'n' is

  • 0
  • 1
  • y = 1.44
  • 1.66
Q.16

Free energy changes for two reaction mechanism 'X' and 'Y are respectively -and - 5 units. It implies that X is

  • slower than Y
  • faster than Y
  • three times slower than Y
  • three times faster than Y
Q.17

The enthalpy change when ammonia gas is dissolved in water is called the heat of

  • solution
  • formation
  • dilution
  • combustion
Q.18

The kinetic energy of gas molecule is zero at

  • 0°C
  • 273°C
  • 100°C
  • -273°C
Q.19

Which law of the thermodynamics provids basis for measuring the thermodynamic property ?

  • First law
  • Zeroth law
  • Third law
  • Second law
Q.20

The chemical potential of any constituent of an ideal solution depends on the __________ of the solution.

  • temperature
  • pressure
  • composition
  • all (a), (b) and (c)
Q.21

Those solutions in which there is no volume change upon mixing the components in the liquid state and which, when diluted do not undergo any heat change (i.e. heat of dilution is zero), are called __________ solutions.

  • ideal
  • real
  • isotonic
  • none of these
Q.22

Which law of the thermodynamics provids basis for measuring the thermodynamic property ?

  • First law
  • Zeroth law
  • Third law
  • Second law
Q.23

__________ calorimeter is normally used for measuring the dryness fraction of steam, when it is very low.

  • Bucket
  • Throttling
  • Separating
  • A combination of separating & throttling
Q.24

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.cm3 and that in vapour phase in 391.1 cm3.Fugacity of water (in kPa) atkPa will be

  • 6738.9
  • 6753.5
  • 7058.3
  • 9000
Q.25

__________ functions are exemplified by heat and work.

  • Path
  • Point
  • State
  • none of these
Q.26

Those solutions in which there is no volume change upon mixing the components in the liquid state and which, when diluted do not undergo any heat change (i.e. heat of dilution is zero), are called __________ solutions.

  • ideal
  • real
  • isotonic
  • none of these
Q.27

In any spontaneous process, the __________ free energy decreases.

  • Helmholtz
  • Gibbs
  • both a & b
  • neither 'a' nor 'b'
Q.28

The equation DU = Tds - PdV is applicable to infinitesimal changes occuring in

  • an open system of constant composition.
  • a closed system of constant composition.
  • an open system with changes in composition.
  • a closed system with changes in composition.
Q.29

The Carnot co-efficient of performance (COP) of a domestic air conditioner compared to a household refrigerator is

  • less
  • more
  • same
  • dependent on climatic conditions
Q.30

In any spontaneous process, the __________ free energy decreases.

  • Helmholtz
  • Gibbs
  • both a & b
  • neither 'a' nor 'b'
Q.31

Which of the following is not an intensive property ?

  • Volume
  • Density
  • Temperature
  • Pressure
Q.32

Gibbs free energy per mole for a pure substance is equal to the

  • latent heat of vaporisation
  • chemical potential
  • molal boiling point
  • heat capacity
Q.33

The gas law (PV = RT) is true for an __________ change.

  • isothermal
  • adiabatic
  • both (a) & (b)
  • neither (a) nor (b)
Q.34

In case of a reversible process (following pvn = constant), work obtained for trebling the volume (v1 = 1 m3 and v2 3 m3 ) is max imum, when the value of 'n' is

  • 0
  • 1
  • y = 1.44
  • 1.66
Q.35

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

  • Stirling
  • Brayton
  • Rankine
  • none of these
Q.36

The unit of fugacity is the same as that of the

  • pressure
  • temperature
  • volume
  • molar concentration
Q.37

The necessary and sufficient condition for equilibrium between two phases is

  • the concentration of each component should be same in the two phases.
  • the temperature of each phase should be same.
  • the pressure should be same in the two phases.
  • the chemical potential of each component should be same in the two phases.
Q.38

Those solutions in which there is no volume change upon mixing the components in the liquid state and which, when diluted do not undergo any heat change (i.e. heat of dilution is zero), are called __________ solutions.

  • ideal
  • real
  • isotonic
  • none of these
Q.39

During a reversible isothermal expansion of an ideal gas, the entropy change is

  • +ve
  • 0
  • -ve
  • ∞
Q.40

Pick out the wrong statement.

  • The values of are zero for a real gas at its critical point.
  • Heat transferred is equal to the change in the enthalpy of the system, for a constant pressure, non-flow, mechanically reversible process.
  • Thermal efficiency of a Carnot engine depends upon the properties of the working fluid besides the source & sink temperatures.
  • During a reversible adiabatic process, the entropy of a substance remains constant.
Q.41

Pick out the correct equation relating 'F' and 'A'.

  • F = A + PV
  • F = E + A
  • F = A - TS
  • F = A + TS
Q.42

Filling of gas from a high pressure cylinder into small bottles is an example of a/an __________ process.

  • equilibrium
  • adiabatic
  • steady
  • unsteady
Q.43

__________ calorimeter is normally used for measuring the dryness fraction of steam, when it is very low.

  • Bucket
  • Throttling
  • Separating
  • A combination of separating & throttling
Q.44

In a reversible process

  • Tds = dE + dW
  • dE - dW = Tds
  • dW - dE = Tds
  • Tds - dW + dE >0
Q.45

A large iceberg melts at the base, but not at the top, because of the reason that

  • ice at the base contains impurities which lowers its melting point.
  • due to the high pressure at the base, its melting point reduces.
  • the iceberg remains in a warmer condition at the base.
  • all (a), (b) and (c).
Q.46

Consider the process A & B shown in the figure given below

In this case, it is possilbe that

  • both the processes are adiabatic.
  • both the processes are isothermal.
  • process A is isothermal while B is adiabatic.
  • process A is adiabatic while B is isothermal.
Q.47

Cv for an ideal gas

  • does not depend upon temperature.
  • is independent of pressure only.
  • is independent of volume only.
  • is independent of both pressure and volume.
Q.48

At the critical point of a substance

  • the surface tension vanishes.
  • liquid and vapour have the same density.
  • there is no distinction between liquid and vapour phases.
  • all (a), (b) and (c).
Q.49
What is the value of ln y (where y = activity co-efficient) for ideal gases?
Q.50
A solid metallic block weighing 5 kg has an initial temperature of 500°C. 40 kg of water initially at 25°C is contained in a perfectly insulated tank. The metallic block is brought into contact with water. Both of them come to equilibrium. Specific heat of block material is 0.4 kJ.kg⁻¹. K⁻¹. Ignoring the effect of expansion and contraction and also the heat capacity to tank, the total entropy change in kJ.kg⁻¹ , K⁻¹ is
0 h : 0 m : 1 s