The heat of vaporisation __________ with increase in pressure.

The forces causing the vaporisation of liquid are derived from the Kinetic energy of translation of its molecules. The heat of vaporisation

A

Increases with pressure rise

B

Decreases with increasing pressure

C

Becomes zero at the critical point

D

Both B & C

An equipment which converts the latent or sensible heat of one fluid into the latent heat of vaporisation of another, is called a

A

Boiler

B

Heat exchanger

C

Recuperator

D

Regenerator

Heat sensitive materials with very high latent heat of vaporisation may be economically separated using

A

Liquid extraction

B

Distillation

C

Evaporation

D

Absorption

For water evaporating into usaturated air under adiabatic conditions and at constant pressure, the __________ remains constant throughout the period of vaporisation.

A

Dry bulb temperature

B

Wet bulb temperature

C

Humidity

D

Relative saturation

At lower temperatures and pressures, the latent heat of vaporisation of a refrigerant

A

Decreases

B

Increases

C

Remains same

D

Depends on other factors

The solvent used in liquid extraction should not have high latent heat of vaporisation, because

A

The pressure drop and hence the pumping cost will be very high

B

It cannot be recovered by distillation

C

Its recovery cost by distillation may be prohibitatively high

D

It will decompose while recovering by distillation

Which of the following is not used for computing latent heat of vaporisation?

A

Clausius-Clayperon equation

B

Reference substance plots based on Durhing & Othmer plots

C

Kistyakowasky's equation

D

Hess

Rate of heat transfer by vaporisation from pools of water is affected by the

A

Nature of heating surface and distribution of bubbles

B

Surface tension of water

C

Viscosity of water

D

All of the above

The latent heat of vaporisation

A

Decreases with increased temperature

B

Decreases as pressure increases

C

Becomes zero at the critical point

D

All of the above

Specific __________ does not change during a phase change (e.g. sublimation, melting, vaporisation etc.).

A

Entropy

B

Internal energy

C

Enthalpy

D

Gibbs free energy

The heat of vaporisation __________ with increase in pressure.

Related Questions