4

Fusion

Vaporisation

Transition

None of these

C. Transition

4

-1.87

0

1.26

3.91

4

# For organic compounds, group contribution method can be used for the estimation of

Critical properties

Specific gravity

Specific volume

Thermal conductivity

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

# Which of the following is a widely used refrigerant in vapour compression refrigeration system (using large centrifugal compressor)?

Freon

Liquid sulphur dioxide

Methyl chloride

Ammonia

4

# At a given temperature, the volume of a gas dissolved in a solvent __________ with increase in pressure.

Increases

Decreases

Remains unchanged

May increase or decrease; depends on the gas

4

1

0

-ve

4

Specific volume

Temperature

Mass

Pressure

4

# In a reversible chemical reaction (where, Δx = number of moles of products-number of moles of reactants)

Addition of inert gas favours the forward reaction, when Δx is positive

Pressure has no effect on equilibrium, when Δn = 0

Addition of inert gas has no effect on the equilibrium constant at constant volume for any value of Δx (+ ve, - ve) or zero)

All 'a', 'b' & 'c'

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

4

# Entropy change of mixing two liquid substances depends upon the

Molar concentration

Quantity (i.e. number of moles)

Both (A) and (B)

Neither (A) nor (B)

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

1

2

3

0

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

Boyle

Inversion

Critical

Reduced

4

Increase

Decrease

No change

None of these

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

# Compressibility factor (i.e., the ratio of actual volume of gas to the volume predicted by ideal gas law) for all gases are

Always greater than one

Same at the same reduced temperature

Same at the same reduced pressure

Both (B) & (C)

4

+ve

0

-ve

4

# For multi-component multiple phases to be in equilibrium at the same pressure and temperature, the __________ of each component must be same in all phases.

Chemical potential

Fugacity

Both (A) and (B)

Neither (A) nor (B)

4

# The internal energy of a gas obeying P (V - b) RT (where, b is a positive constant and has a constant Cv), depends upon its

Pressure

Volume

Temperature

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

4

Temperature

Pressure

Volume

Entropy

4

-ve

0

+ve

4

Infinity

Unity

Constant

Negative

4

Zero

Unity

Infinity

Negative

4

0

Maximum

Minimum

4

Steam engine

Carnot engine

Diesel engine

Otto engine

4

# Critical solution temperature (or the consolute temperature) for partially miscible liquids (e.g., phenol-water) is the minimum temperature at which

A homogeneous solution (say of phenol water) is formed

Mutual solubility of the two liquids shows a decreasing trend

Two liquids are completely separated into two layers

None of these

4

# Refrigerants commonly used for domestic refrigerators are

Ethyl chloride or methyl chloride

Freon-12

Propane

NH3 or CO2

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)