4

# If different processes are used to bring about the same chemical reaction, the enthalpy change is same for all of them. This is __________ law.

Hess's

Kirchoff's

Lavoisier and Laplace

None of these

A. Hess's

4

Temperature

Pressure

Volume

None of these

4

Isothermal

Isentropic

Isobaric

4

# Pick out the wrong statement.

The values of (∂P/∂V)T and (∂2P/∂V2)T 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

4

# Gibbs-Helmholtz equation is

ΔF = ΔH + T [∂(ΔF)/∂T]P

ΔF = ΔH - TΔT

d(E - TS) T, V < 0

dP/dT = ΔHvap/T.ΔVvap

4

# 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

4

# High __________ is an undesirable property for a good refrigerant.

Specific heat

Latent heat of vaporisation

Viscosity

Specific vapor volume

4

100,000 kW

160,000 kW

200,000 kW

320,000 kW

4

300 × (32/7)

300 × (33/5)

300 × (333/7)

300 × (35/7)

4

# On opening the door of an operating refrigerator kept in a closed room, the temperature of the room will

Increase

Decrease

Remain same

Increase in summer and will decrease in winter

4

(∂E/∂T)V

(∂E/∂V)T

(∂E/∂P)V

(∂V/∂T)P

4

Critical

Boyle

Inversion

Reduced

4

# The quantitative effect of temperature on chemical equilibrium is given by the

Vant-Hoff equation

Le-Chatelier's principle

Arrhenius equation

None of these

4

# Gibbs-Duhem equation

States that n11 + n22 + ....njj = 0, for a system of definite composition at constant temperature and pressure

Applies only to binary systems

Finds no application in gas-liquid equilibria involved in distillation

None of these

4

# 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)

4

Isothermal

Isobaric

Polytropic

4

# Enthalpy changes over a constant pressure path are always zero for __________ gas.

Any

A perfect

An easily liquefiable

A real

4

# Mollier diagram is a plot of

Temperature vs. enthalpy

Temperature vs. enthalpy

Entropy vs. enthalpy

Temperature vs. internal energy

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

P + F - C = 2

C = P - F + 2

F = C - P - 2

P = F - C - 2

4

# 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

4

# The expression, ΔG = nRT. ln(P2/P1), gives the free energy change

With pressure changes at constant temperature

Under reversible isothermal volume change

During heating of an ideal gas

During cooling of an ideal gas

4

# Lowering of condenser temperature (keeping the evaporator temperature constant) in case of vapour compression refrigeration system results in

Increased COP

Same COP

Decreased COP

Increased or decreased COP; depending upon the type of refrigerant

4

# In a homogeneous solution, the fugacity of a component depends upon the

Pressure

Composition

Temperature

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

4

# The internal energy of an incompressible fluid depends upon its

Pressure

Temperature

Both (A) & (B)

Neither (A) nor (B)

4

0.5

3.5

4.5

8.5

4

Zero

Unity

Infinity

None of these

4

# In the reaction, represented by, 2SO2 + O2 2SO3; ΔH = - 42 kcal; the forward reaction will be favoured by

Low temperature

High pressure

Both (A) and (B)

Neither (A) nor (B)

4

Temperature

Pressure

Volume

Entropy

4

x

x + 1

x + 2

x + 3