4

# The value of gas constant 'R' is

1.987 cal/gm mole °K

1.987 BTU/lb. mole °R

Both (A) and (B)

Neither (A) nor (B)

C. Both (A) and (B)

4

# Solubility of a substance which dissolves with an increase in volume and liberation of heat will be favoured by the

Low pressure and high temperature

Low pressure and low temperature

High pressure and low temperature

High pressure and high temperature

4

# A solid is transformed into vapour without going to the liquid phase at

Triple point

Boiling point

Below triple point

Always

4

# Which one is true for a throttling process?

A gas may have more than one inversion temperatures

The inversion temperature is different for different gases

The inversion temperature is same for all gases

The inversion temperature is the temperature at which Joule-Thomson co-efficient is infinity

4

# It is desired to bring about a certain change in the state of a system by performing work on the system under adiabatic conditions.

The amount of work needed is path dependent

Work alone cannot bring out such a change of state

The amount of work needed is independent of path

More information is needed to conclude anything about the path dependence or otherwise of the work needed

4

# 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

4

Isothermal

Isometric

None of these

4

The same

Less than

Greater than

Different than

4

# Free energy

Decreases in all spontaneous (or irreversible) processes

Change during a spontaneous process has a negative value

Remains unchanged in reversible processes carried at constant temperature and pressure

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

4

# To obtain integrated form of Clausius-Clapeyron equation, ln (P2/P1) = (ΔHV/R) (1/T1 - 1/T2) from the exact Clapeyron equation, it is assumed that the

Volume of the liquid phase is negligible compared to that of vapour phase

Vapour phase behaves as an ideal gas

Heat of vaporisation is independent of temperature

All (A), (B) & (C)

4

# 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)

4

# (∂T/∂P)H is the mathematical expression for

Specific heat at constant pressure (Cp)

Specific heat at constant volume (Cv)

Joule-Thompson co-efficient

None of these

4

# Pick out the undesirable property for a good refrigerant.

High thermal conductivity

Low freezing point

Large latent heat of vaporisation

High viscosity

4

# __________ increases with increase in pressure.

The melting point of wax

The boiling point of a liquid

Both (A) and (B)

Neither (A) nor (B)

4

# Air-refrigeration cycle

Is the most efficient of all refrigeration cycles

Has very low efficiency

Requires relatively large quantities of air to achieve a significant amount of refrigeration

Both (B) and (C)

4

# Gibbs free energy (G) is represented by, G = H - TS, whereas Helmholtz free energy, (A) is given by, A = E - TS. Which of the following is the Gibbs-Helmholtz equation?

[∂(G/T)/∂T] = - (H/T2)

[∂(A/T)/∂T]V = - E/T2

Both (A) and (B)

Neither (A) nor (B)

4

# (∂H/∂T)P is the mathematical expression for

CV

Entropy change

Gibbs free energy

None of these

4

# Pick out the wrong statement.

Trouton's ratio of non-polar liquids is calculated using Kistyakowsky equation

Thermal efficiency of a Carnot engine is always less than 1

An equation relating pressure, volume and temperature of a gas is called ideal gas equation

None of these

4

# Normal temperature and pressure (N.T.P.) corresponds to

0°C and 760 mm Hg

15°C and 760 mm Hg

20°C and 760 mm Hg

0°C and 1 kgf/cm2

4

# Boiling of liquid is accompanied with increase in the

Vapor pressure

Specific Gibbs free energy

Specific entropy

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

4

# The expression for entropy change, ΔS = n Cp . ln (T2/T1), is valid for the __________ of a substance.

Simultaneous pressure & temperature change

Heating

Cooling

Both (B) and (C)

4

H = E - PV

H = F - TS

H - E = PV

None of these

4

# 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 behaves similarly

None of these

4

# Which of the following is not an equation of state?

Bertholet equation

Clausius-Clapeyron equation

Beattie-Bridgeman equation

None of these

4

# The intensive properties are

Molar volume, density, viscosity and boiling point

Refractive index and surface tension

Both (A) and (B)

None of these

4

RT d ln P

RT d ln f

R d ln f

None of these

4

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

Internal energy

Enthalpy

Gibbs free energy

Helmholtz free energy

4

Reversible

Irreversible

Isothermal

4

# Which of the following identities can be most easily used to verify steam table data for superheated steam?

(∂T/∂V)S = (∂p/∂S)V

(∂T/∂P)S = (∂V/∂S)P

(∂P/∂T)V = (∂S/∂V)T

(∂V/∂T)P = -(∂S/∂P)T

4

√(2KT/m)

√(3KT/m)

√(6KT/m)

3KT/m