4

# dW and dq are not the exact differential, because q and W are

State functions

Path functions

Intensive properties

Extensive properties

B. Path functions

4

0.15

1.5

4.5

6.5

4

# Pick out the wrong statement.

Activity co-efficient is dimensionless.

In case of an ideal gas, the fugacity is equal to its pressure.

In a mixture of ideal gases, the fugacity of a component is equal to the partial pressure of the component.

The fugacity co-efficient is zero for an ideal gas

4

# 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

4

# 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

4

# Consider the process A & B shown in the figure given below: In this case, it is possible that

Both the processes are isothermal

Process A is isothermal while B is adiabatic

Process A is adiabatic while B is isothermal

4

Carnot

Air

Absorption

vapour-ejection

4

# The Maxwell relation derived from the differential expression for the Helmholtz free energy (dA) is

(∂T/∂V)S = - (∂P/∂S)V

(∂S/∂P)T = - (∂V/∂T)P

(∂V/∂S)P = (∂T/∂P)S

(∂S/∂V)T = (∂P/∂T)V

4

1

< 1

> 1

>> 1

4

R loge 4

R log10 4

Cv log10 4

Cv loge 4

4

# Two substances are in equilibrium in a reversible chemical reaction. If the concentration of each substance is doubled, then the value of the equilibrium constant will be

Same

Doubled

Halved

One fourth of its original value

4

# When a gas is subjected to adiabatic expansion, it gets cooled due to

Decrease in velocity

Decrease in temperature

Decrease in kinetic energy

Energy spent in doing work

4

0

1

2

3

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

Infinity

Minus infinity

Zero

None of these

4

F = A + PV

F = E + A

F = A - TS

F = A + TS

4

Enthalpy

Entropy

Pressure

None of these

4

# During Joule-Thomson expansion of gases

Enthalpy remains constant

Entropy remains constant

Temperature remains constant

None of these

4

# Fugacity is a measure of the

Escaping tendencies of the same substance in different phases of a system

Relative volatility of a mixture of two miscible liquids

Behaviour of ideal gases

None of these

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

# Heat of reaction at constant volume is identified with __________ change.

Enthalpy

Internal energy

Either (A) or (B)

Neither (A) nor (B)

4

Isothermal

Isometric

None of these

4

P + F - C = 2

C = P - F + 2

F = C - P - 2

P = F - C - 2

4

# Which is an example of closed system?

Air compressor

Liquid cooling system of an automobile

Boiler

None of these

4

Sub-cooled

Saturated

Non-solidifiable

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

# For an incompressible fluid, the __________ is a function of both pressure as well as temperature.

Internal energy

Enthalpy

Entropy

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

4

# (1/V) (∂V/∂T)P is the mathematical expression

Joule-Thomson co-efficient

Specific heat at constant pressure (Cp)

co-efficient of thermal expansion

Specific heat at constant volume (CV)

4

# 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

4

0

1

2

3