4

T

√T

T2

1/√T

A. T

4

Zero

Negative

More than zero

Indeterminate

4

# Pick out the wrong statement.

A refrigeration cycle violates the second law of thermodynamics

Refrigeration cycle is normally represented by a temperature vs. entropy plot

In a refrigerator, work required decreases as the temperature of the refrigerator and the temperature at which heat is rejected increases

One ton of refrigeration is equivalent to the rate of heat absorption equal to 3.53 kW

4

Isothermally

Isobarically

None of these

4

+ve

0

-ve

4

# Pick out the correct statement.

Like internal energy and enthalpy, the absolute value of standard entropy for elementary substances is zero

Melting of ice involves increase in enthalpy and a decrease in randomness

The internal energy of an ideal gas depends only on its pressure

Maximum work is done under reversible conditions

4

Zero

50%

Almost 100%

unpredictable

4

# The equation, (d loge PA/d loge xA) = (d loge PA/d loge xB) applicable to a binary solution of components. A and B in equilibrium with their vapors at constant temperature and pressure is called the __________ equation.

Van Laar

Margules

Gibbs-Duhem

Gibbs-Duhem-Margules

4

Low T, low P

High T, high P

Low T, high P

High T, low P

4

# With increase in pressure (above atmospheric pressure), the Cp of a gas

Increases

Decreases

Remains unchanged

First decreases and then increases

4

Zeroth

First

Second

Third

4

# In an ideal solution, the activity of a component equals its

Mole fraction

Fugacity at the same temperature and pressure

Partial pressure

None of these

4

# Air-refrigeration cycle

Is the most efficient of all refrigeration cycles

Has very low efficiency

Requires relatively large quantities of air to achieve a significant amount of refrigeration

Both (B) and (C)

4

Tds = dE + dW

dE - dW = Tds

dW - dE = Tds

Tds - dW + dE >0

4

ds = 0

ds <0

ds > 0

ds = Constant

4

# When liquid and vapour phase of multi-component system are in equilibrium (at a given temperature and pressure), then chemical potential of each component is

Same in both the phases

Zero in both the phases

More in vapour phase

More in liquid phase

4

# Mollier diagram is a plot of

Temperature vs. enthalpy

Temperature vs. enthalpy

Entropy vs. enthalpy

Temperature vs. internal energy

4

Heat

Momentum

Energy

Work

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

# dW and dq are not the exact differential, because q and W are

State functions

Path functions

Intensive properties

Extensive properties

4

# The third law of thermodynamics states that the

Heat capacity of a crystalline solid is zero at absolute zero temperature

Heat transfer from low temperature to high temperature source is not possible without external work

Gases having same reduced properties behaves similarly

None of these

4

Mass

Energy

Momentum

None of these

4

2HI H2 + I2

N2O4 2NO2

2SO2 + O2 2SO3

None of these

4

Negative

Zero

Infinity

None of these

4

# The extensive properties are

Volume, mass and number of moles

Free energy, entropy and enthalpy

Both (A) and (B)

None of these

4

# Out of the following refrigeration cycles, which one has maximum COP?

Air cycle

Carnot cycle

Ordinary vapor compression cycle

Vapor compression with a reversible expansion engine

4

# Equilibrium constant of a reaction varies with the

Initial concentration of the reactant

Pressure

Temperature

None of these

4

# Melting of ice exemplifies a/an

Endothermic reaction

Exothermic reaction

Process involving a chemical reaction

4

# A gas shows deviation from ideal behaviour at

Low pressure and high temperature

Low pressure and low temperature

Low temperature and high pressure

High temperature and high pressure

4

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

Increases

Decreases

Remains unchanged

Decreases linearly