Q.1

Fugacity and pressure are numerically equal, when the gas is

  • in standard state
  • at high pressure
  • at low temperature
  • in ideal state
Q.2

Which of the following has the minimum value of COP for a given refrigeration effect?

  • Reverse Carnot cycle.
  • Ordinary vapour-compression cycle.
  • Vapour-compression process with a reversible expansion engine.
  • Air refrigeration cycle.
Q.3

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

  • more
  • less
  • same
  • unpredictable; depends on the particular reaction
Q.4

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

  • He
  • N2
  • O2
  • H2
Q.5

What happens in a reversible adiabatic compression ?

  • Heating occurs
  • Cooling occurs
  • Pressure is constant
  • Temperature is constant
Q.6

Which of the following is not an intensive property ?

  • Molar heat capacity
  • Internal energy
  • Viscosity
  • None of these
Q.7

Which of the following has the minimum value of COP for a given refrigeration effect?

  • Reverse Carnot cycle.
  • Ordinary vapour-compression cycle.
  • Vapour-compression process with a reversible expansion engine.
  • Air refrigeration cycle.
Q.8

Refrigerants commonly used for domestic refrigerators are

  • ethyl chloride or methyle chloride
  • freon-12
  • propane
  • NH3 or CO2.
Q.9

__________ decreases during adiabatic throttling of a perfect gas.

  • Entropy
  • Temperature
  • Enthalpy
  • Pressure
Q.10

Efficiency of a Carnot engine working between temperatures T1 and T2 (T1 < T) is

Q.11

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

  • adiabatic
  • isometric
  • isentropic
  • isothermal
Q.12

For multicomponent multiple phases to be in equilibrium at the same pressure and temperature, the __________ of each component must be same in all phases.

  • chemical potential
  • fugacity
  • both (a) and (b)
  • neither (a) nor (b)
Q.13

The work done in isothermal compression compared to that in adiabatic compression will be

  • less
  • more
  • same
  • more or less depending upon the extent of work done
Q.14

Ideal gas law is applicable at

  • low T, low P
  • high T, high P
  • low T, high P
  • high T, low P
Q.15

Sublimation temperature of dry ice (solid CO2) is __________ °C.

  • -273
  • 0
  • -78
  • 5
Q.16

Pick out the wrong statement.

  • At constant pressure, solubility of a gas in a liquid diminishes with rise in temperature.
  • Normally, the gases which are easily liquified, are more soluble in common solvents.
  • The gases which are capable of forming ions in aqueous solution, are much more soluble in water than in other solvents.
  • At constant pressure, solubility of a gas in a liquid increases with rise in temperature.
Q.17

Solid and liquid phases of a substance are in equilibrium at the

  • critical temperature
  • melting point.
  • freezing point.
  • both (b) and (c).
Q.18

Absolute zero temperature signifies the

  • minimum temperature attainable.
  • temperature of the heat reservoir to which a Carnot engine rejects all the heat that is taken in.
  • temperature of the heat reservoir to which a Carnot engine rejects no heat.
  • none of these.
Q.19

Joule-Thomson co-efficient is defined as

Q.20

Pick out the wrong statement.

  • Minimum number of degree of freedom of a system is zero.
  • Degree of freedom of a system containing a gaseous mixture of helium, carbon dioxide and hydrogen is 4.
  • For a two phase system in equilibrium made up of four non-reacting chemical species, the number of degrees of freedom is 4.
  • Enthalpy and internal energy change is zero during phase change processes like melting, vaporisation and sublimation.
Q.21

Tea kept in a thermos flask is vigorously shaken. If the tea is considered as a system, then its temperature will

  • increase
  • decrease
  • remain unchanged
  • first fall and then rise.
Q.22

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

  • pressure
  • temperature
  • composition
  • all (a), (b) and (c)
Q.23

During adiabatic expansion of gas

  • pressure remains constant.
  • pressure is increased.
  • temperature remains constant.
  • none of these.
Q.24

The efficiency of an Otto engine compared to that of a diesel engine, for the same compression ratio will be

  • more
  • less
  • same
  • data insufficient to predict
Q.25

Reduced pressure of a gas is the ratio of its

  • pressure to critical pressure.
  • critical pressure to pressure.
  • pressure to pseudocritical pressure.
  • pseudocritical pressure to pressure.
Q.26

For a reversible process involving only pressure-volume work

  • (dF)T, p < 0
  • (dF)T, p > 0
  • (dF)T, p = 0
  • (dA)T, v < 0
Q.27

If atmospheric temperature and dew point are nearly equal, then the relative humidity is

  • zero
  • 50%
  • almost 100%
  • unpredictable
Q.28

In case of steady flow compression polytropic process (PVn = constant), the work done on air is the lowest, when

  • n = y = 1.4
  • n = 0
  • n = 1
  • n = 1.66
Q.29

A liquid under pressure greater than its vapour pressure for the temperature involved is called a __________ liquid.

  • subcooled
  • saturated
  • non-solidifiable
  • none of these
Q.30

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

  • reversible isothermal
  • irreversible isothermal
  • reversible adiabatic
  • none of these
Q.31

Gibbs-Duhem equation relates composition in liquid phase and the __________ at constant temperature & pressure.

  • fugacity
  • partial pressure
  • activity co-efficient
  • (a), (b), and (c)
Q.32

Mollier chart is a __________ plot.

  • pressure vs enthalpy
  • pressure vs volume
  • enthalpy vs entropy
  • temperature vs entropy
Q.33

For organic compounds, group contribution method can be used for the estimation of

  • critical properties.
  • specific gravity.
  • specific volume.
  • thermal conductivity.
Q.34

Specific __________ does not change during phase change at constant temperature and pressure.

  • entropy
  • Gibbs energy
  • internal energy
  • enthalpy
Q.35

Air enters an adiabatic compressor at 300K. The exit temperature for a compression ratio ofassuming air to be an ideal gas (Y = Cp/Cv = 7/and the process to be reversible, is

  • 300(32/7)
  • 300(33/5)
  • 300(333/7)
  • 300(35/7)
Q.36

Absorption/evolution of heat during conversion of a substance from one allotropic form to another is termed as the heat of

  • sublimation
  • fusion
  • transition
  • vaporisation
Q.37

For a real gas, the chemical potential is given by

  • RT dlnP
  • RT dlnf
  • R dlnf
  • none of these
Q.38

When dilute aqueous solutions of two salts are mixed, the process is associated with

  • decrease in temperature.
  • increase in temperature.
  • no change in temperature.
  • change in temperature which is a function of composition.
Q.39

In an ideal solution, the activity of a component equals its

  • mole fraction.
  • fugacity at the same temperature and pressure.
  • partial pressure.
  • none of these.
Q.40

The third law of thermodynamics states that the

  • heat capacity of a crystalline solid is zero at absolute zero temperature.
  • heat transfer from low temperature to high temperature source is not possible without external work.
  • gases having same reduced properties behave similarly.
  • none of these.
Q.41

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

  • more in vapour phase.
  • more in liquid phase.
  • same in both the phases.
  • replaced by chemical potential which is more in vapour phase.
Q.42

Entropy change for an irreversible process taking system and surrounding together is

  • 0
  • > 0
  • < 0
  • none of these
Q.43

At absolute zero temperature, all substances have the same

  • heat capacity
  • crystalline structure
  • entropy
  • none of these
Q.44

Pick out the correct statement.

  • Like internal energy and enthalphy, the absolute value of standard entropy for elementary substances is zero.
  • Melting of ice involves increase in enthalpy and a decrease in randomness.
  • The internal energy of an ideal gas depends only on its pressure.
  • Maximum work is done under reversible conditions.
Q.45

Chemical engineering thermodynamics is concerned with the __________ in/of chemical processes.

  • reaction mechanism
  • calculation of rates
  • energy transformation from one form to the another
  • none of these
Q.46

A gas has a volume of 27.3 c.c. at 0°C. Its volume at 10°C (if pressure remains unchanged) will be __________ c.c.

  • 2.73
  • 28.3
  • 273
  • 283
Q.47

In the equation, PVn = constant, if the value of n is in between 1 and y (i.e. Cp/Cv), then it represents a reversible __________ process.

  • isometric
  • polytropic
  • isentropic
  • isobaric
Q.48

Entropy of an ideal gas depends upon its

  • pressure
  • temperature
  • both (a) & (b)
  • neither (a) nor (b)
Q.49

Linde gas liquefaction process employs cooling

  • by throttling
  • by expansion in an engine
  • at constant pressure
  • none of these
Q.50

In a reversible chemical reaction (where, Δx = number of moles of products-number of moles of reactants )

  • addition of inert gas favours the forward reaction, when Δx is positive.
  • pressure has no effect on equilibrium, when Δn = 0.
  • addition of inert gas has no effect on the equilibrium constant at constant volume for any value of Δx (+ ve, - ve) or zero).
  • all 'a', 'b' & 'c'.
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