4

# Clapeyron Equation deals with the

Rate of change of vapour pressure with temperature

Effect of an inert gas on vapour pressure

Calculation of ΔF for spontaneous phase change

Temperature dependence of heat of phase transition

A. Rate of change of vapour pressure with temperature

4

# The expression for entropy change, ΔS = n Cp . ln (T2/T1), is valid for the __________ of a substance.

Simultaneous pressure & temperature change

Heating

Cooling

Both (B) and (C)

4

# Water on heating from 1 to 4°C

Contracts

Expands

Has same volume

May contract or expand

4

# Choose the condition that must be specified in order to liquify CO2 (triple point for CO2 is - 57°C and 5.2 atm).

Pressure must be kept below 5.2 atm

Temperature must be kept above - 57°C

Pressure must be kept below 5.2 atm. and temperature must be kept above 57°C

Pressure and temperature must be kept below 5.2 atm. and - 57°C respectively

4

# Entropy is a/an

State function

Macroscopic property

Extensive property

None of these

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

Positive

Negative

Zero

Infinity

4

+ve

0

-ve

4

Molten sodium

Mercury

Molten potassium

4

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

Enhanced COP

Decreased COP

No change in the value of COP

Increased or decreased COP; depending upon the type of refrigerant

4

Minimum

Zero

Maximum

None of these

4

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

Increases

Decreases

Remain same

Decreases linearly

4

# The expression, nRT ln(P1/P2), is for the __________of an ideal gas.

Compressibility

Work done under isothermal condition

Co-efficient of thermal expansion

4

n = y = 1.4

n = 0

n = 1

n = 1.66

4

# Trouton's ratio of __________ liquids is calculated using Kistyakowsky equation.

Polar

Non-polar

Both (A) & (B)

Neither (A) nor (B)

4

4 J

0

8 J

4

-2 RT ln 0.5

-RT ln 0.5

0.5 RT

2 RT

4

Carnot

Air

Absorption

vapour-ejection

4

# Free energy change of mixing two liquid substances is a function of the

Concentration of the constituents only

Quantities of the constituents only

Temperature only

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

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

# All gases above its inversion temperature, in a throttling process will show

A heating effect

No change in temperature

A cooling effect

Either (A) or (C)

4

dQ = dE + dW

dQ = dE - dW

dE = dQ + dW

dW = dQ + dE

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

# During the phase transition, __________ changes.

Pressure

Volume

Temperature

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

4

# Boiling of liquid is accompanied with increase in the

Vapor pressure

Specific Gibbs free energy

Specific entropy

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

4

50 kcal/hr

200 BTU/hr

200 BTU/minute

200 BTU/day

4

# Which of the following will increase the volume of a real gas by four times?

Doubling the absolute temperature as well as pressure of the gas

Reducing pressure to one fourth at constant temperature

Reducing temperature to one fourth at constant pressure

Reducing the temperature to half and doubling the pressure

4

0

1

2

3

4

# Joule-Thomson co-efficient depends on the

Pressure

Temperature

Both (A) & (B)

Neither (A) nor (B)

4

+ve

0

-ve