4

# As the temperature is lowered towards the absolute zero, the value of ∂(ΔF)/∂T, then approaches

Unity

Zero

That of the heat of reaction

Infinity

B. Zero

4

Oxygen

Nitrogen

Air

Hydrogen

4

dE = Tds - PdV

dQ = CvdT + PdV

dQ = CpdT + Vdp

Tds = dE - PdV

4

Stirling

Brayton

Rankine

None of these

4

0

< 0

> 0

4

12 P1V1

6 P1 V1

3 P1V1

P1 V1

4

# The melting point of paraffin wax (which contracts on solidification) __________ with pressure rise.

Increases

Decreases

Remains unchanged

Decreases linearly

4

Freon-12

Ethylene

Ammonia

Carbon dioxide

4

# The equation relating E, P, V and T which is true for all substances under all conditions is given by (∂E/∂V)T = T(∂P/∂T)H - P. This equation is called the

Maxwell's equation

Thermodynamic equation of state

Equation of state

Redlich-Kwong equation of state

4

# Entropy is a/an

State function

Macroscopic property

Extensive property

None of these

4

# Pick out the wrong statement.

An ideal liquid or solid solution is defined as one in which each component obeys Raoult's law

If Raoult's law is applied to one component of a binary mixture; Henry's law or Raoult's law is applied to the other component also

Henry's law is rigorously correct in the limit of infinite dilution

None of these

4

P + F - C = 2

C = P - F + 2

F = C - P - 2

P = F - C - 2

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

Temperature

Specific heat

Volume

Pressure

4

# Fugacity co-efficient of a substance is the ratio of its fugacity to

Mole fraction

Activity

Pressure

Activity co-efficient

4

V1/V2

V2/V1

V1 - V2

V1.V2

4

# The rate at which a substance reacts is proportional to its active mass and the rate of a chemical reaction is proportional to the product of active masses of the reacting substances. This is the

Lewis-Randall rule

Statement of Van't Hoff Equation

Le-Chatelier's principle

None of these

4

Bomb

Separating

Bucket

Throttling

4

# Entropy is a measure of the __________ of a system.

Disorder

Orderly behaviour

Temperature changes only

None of these

4

# The thermodynamic law, PVy = constant, is not applicable in case of

Ideal compression of air

Free expansion of an ideal gas

Adiabatic expansion of steam in a turbine

Adiabatic compression of a perfect gas

4

# On a P-V diagram of an ideal gas, suppose a reversible adiabatic line intersects a reversible isothermal line at point A. Then at a point A, the slope of the reversible adiabatic line (∂P/∂V)s and the slope of the reversible isothermal line (∂P/ ∂V)T are related as (where, y = Cp/Cv)

(∂P/∂V)S = (∂P/∂V)T

(∂P/∂V)S = [(∂P/∂V)T]Y

(∂P/∂V)S = y(∂P/∂V)T

(∂P/∂V)S = 1/y(∂P/∂V)T

4

He

N2

O2

H2

4

Infinity

Minus infinity

Zero

None of these

4

# An ideal liquid refrigerant should

Not have a sub-atmospheric vapour pressure at the temperature in the refrigerator coils

Not have unduly high vapour pressure at the condenser temperature

Both (A) and (B)

Have low specific heat

4

dE = CpdT

dE = CvdT

dQ = dE + pdV

dW = pdV

4

# 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

4

# A refrigeration cycle is a reversed heat engine. Which of the following has the maximum value of the co-efficient of performance (COP) for a given refrigeration effect?

Vapor compression cycle using expansion valve

Air refrigeration cycle

Vapor compression cycle using expansion engine

Carnot refrigeration cycle

4

# 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

4

# The internal energy of an incompressible fluid depends upon its

Pressure

Temperature

Both (A) & (B)

Neither (A) nor (B)

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)