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

Simultaneous pressure & temperature change

Heating

Cooling

Both (B) and (C)

Contracts

Expands

Has same volume

May contract or expand

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

State function

Macroscopic property

Extensive property

None of these

Volume

Mass

Critical temperature

None of these

Positive

Negative

Zero

Infinity

+ve

0

-ve

∞

Molten sodium

Molten lead

Mercury

Molten potassium

Enhanced COP

Decreased COP

No change in the value of COP

Increased or decreased COP; depending upon the type of refrigerant

Minimum

Zero

Maximum

None of these

Increases

Decreases

Remain same

Decreases linearly

Compressibility

Work done under adiabatic condition

Work done under isothermal condition

Co-efficient of thermal expansion

n = y = 1.4

n = 0

n = 1

n = 1.66

Polar

Non-polar

Both (A) & (B)

Neither (A) nor (B)

4 J

∞

0

8 J

-2 RT ln 0.5

-RT ln 0.5

0.5 RT

2 RT

Carnot

Air

Absorption

vapour-ejection

Concentration of the constituents only

Quantities of the constituents only

Temperature only

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

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

A heating effect

No change in temperature

A cooling effect

Either (A) or (C)

dQ = dE + dW

dQ = dE - dW

dE = dQ + dW

dW = dQ + dE

Increase

Decrease

Remain unchanged

First fall and then rise

Pressure

Volume

Temperature

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

Vapor pressure

Specific Gibbs free energy

Specific entropy

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

50 kcal/hr

200 BTU/hr

200 BTU/minute

200 BTU/day

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

0

1

2

3

Pressure

Temperature

Both (A) & (B)

Neither (A) nor (B)

∞

+ve

0

-ve

A real gas on expansion in vacuum gets heated up

An ideal gas on expansion in vacuum gets cooled

An ideal gas on expansion in vacuum gets heated up

A real gas on expansion in vacuum cools down whereas ideal gas remains unaffected