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

C. (∂P/∂V)S = y(∂P/∂V)T

4

# If two gases have same reduced temperature and reduced pressure, then they will have the same

Volume

Mass

Critical temperature

None of these

4

# Throttling process is a/an __________ process.

Reversible and isothermal

Irreversible and constant enthalpy

Reversible and constant entropy

Reversible and constant enthalpy

4

Cp < Cv

Cp = Cv

Cp > Cv

C ≥ Cv

4

Zeroth

First

Second

Third

4

Temperature

Mass

Volume

Pressure

4

# With increase in reduced temperature, the fugacity co-efficient of a gas at constant reduced pressure

Increases

Decreases

Remain same

Decreases linearly

4

No

Any real

Only ideal

Both (B) and (C)

4

# In vapour compression refrigeration system, if the evaporator temperature and the condenser temperatures are -13°C and 37°C respectively, the Carnot COP will be

5.2

6.2

0.168

Data insufficient, can't be found out

4

# Equilibrium constant of a reaction varies with the

Initial concentration of the reactant

Pressure

Temperature

None of these

4

0

1

2

3

4

RT d ln P

RT d ln f

R d ln f

None of these

4

# Out of the following refrigeration cycles, which one has the minimum COP (Co-efficient of performance)?

Air cycle

Carnot cycle

Ordinary vapour compression cycle

Vapour compression with a reversible expansion engine

4

# A Carnot cycle consists of the following steps:

Two isothermal and two isentropic

Two isobaric and two isothermal

Two isochoric and two isobaric

Two isothermals and two isochoric

4

-94 kcal

> -94 kcal

< - 94 kcal

Zero

4

# Clausius-Clapeyron Equation gives accurate result, when the

Vapour pressure is relatively low and the temperature does not vary over wide limits

Vapour obeys the ideal gas law and the latent heat of vaporisation is constant

Volume in the liquid state is negligible compared with that in the vapour state

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

4

# The effect of changing the evaporator temperature on COP as compared to that of changing the condenser temperature (in vapour compression refrigeration system) is

Less pronounced

More pronounced

Equal

Data insufficient, can't be predicted

4

# Activity co-efficient is a measure of the

Departure from ideal solution behaviour

Departure of gas phase from ideal gas law

Vapour pressure of liquid

None of these

4

Straight line

Sine curve

Parabola

Hyperbola

4

# Compound having large heat of formation is

More stable

Less stable

Not at all stable (like nascent O2)

Either more or less stable; depends on the compound

4

# Pick out the wrong statement:

The expansion of a gas in vacuum is an irreversible process

An isometric process is a constant pressure process

Entropy change for a reversible adiabatic process is zero

Free energy change for a spontaneous process is negative

4

# When a system in equilibrium is subjected to a change in temperature, pressure or concentration, the equilibrium is displaced in a direction which tends to undo the effect of the change. This is called the

Le-Chatelier principle

Kopp's rule

Law of corresponding state

Arrhenius hypothesis

4

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

Increases

Decreases

Remains unchanged

Decreases linearly

4

# For an exothermic reaction

Only enthalpy change (ΔH) is negative

Only internal energy change (ΔE) is negative

Both ΔH and ΔE are negative

Enthalpy change is zero

4

Specific volume

Work

Pressure

Temperature

4

# Which of the following is true for Virial equation of state?

Virial co-efficients are universal constants

Virial co-efficients 'B' represents three body interactions

Virial co-efficients are function of temperature only

For some gases, Virial equations and ideal gas equations are the same

4

Water

Air

Evaporative

Gas

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

# Pick out the wrong statement.

Enthalpies of all elements in their standard states are assumed to be zero

Combustion reactions are never endothermic in nature

Heat of reaction at constant volume is equal to the change in internal energy

Clausius-Clapeyron equation is not applicable to melting process

4

# 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

4

# A cylinder contains 640 gm of liquid oxygen. The volume occupied (in litres) by the oxygen, when it is released and brought to standard conditions (0°C, 760 mm Hg) will be __________ litres.

448

224

22.4

Data insufficient; can't be computed