INDIABIX-CHE THERMODYNAMICS

Question 1

Maximum work that could be secured by expanding the gas over a given pressure range is the __________ work.

isothermal
adiabatic
isentropic
none of these

Answer 1

isothermal

Question 2

Internal energy change of a system over one complete cycle in a cyclic process is

zero
+ve
-ve
dependent on the path

Answer 2

zero

Question 3

Heating of water under atmospheric pressure is an __________ process.

isochoric
isobaric
adiabatic
isothermal

Answer 3

isobaric

Question 4

Van Laar equation deals with the activity co-efficients in

binary solutions
ternary solutions
azeotropic mixture only
none of these

Answer 4

binary solutions

Question 5

High __________ is an undesirable property for a good refrigerant.

specific heat
latent heat of vaporisation
viscosity
specific vapor volume

Answer 5

viscosity

Question 6

Solubility of a substance which dissolves with an increase in volume and liberation of heat will be favoured by the

low pressure and high temperature.
low pressure and low temperature.
high pressure and low temperature.
high pressure and high temperature.

Answer 6

low pressure and low temperature.

Question 7

A chemical reaction will occur spontaneously at constant pressure and temperature, if the free energy is

zero
positive
negative
none of these

Answer 7

negative

Question 8

Fundamental principle of refrigeration is based on the __________ law of thermodynamics.

zeroth
first
second
third

Answer 8

second

Question 9

For a spontaneous process, free energy

is zero
increases
decreases whereas the entropy increases
and entropy both decrease

Answer 9

decreases whereas the entropy increases

Question 10

A refrigeration cycle is a reversed heat engine. Which of the following has the maximum value of the co-efficient of performance (COP) for a given refrigeration effect ?

Vapor compression cycle using expansion valve.
Air refrigeration cycle.
Vapor compression cycle using expansion engine.
Carnot refrigeration cycle.

Answer 10

Carnot refrigeration cycle.

Question 11

In a working refrigerator, the value of COP is always

0
< 0
< 1
> 1

Answer 11

> 1

Question 12

A refrigerator may be termed as a

heat pump
heat engine
Carnot engine
none of these

Answer 12

heat pump

Question 13

Measurement of thermodynamic property of temperature is facilitated by __________ law of thermodynamics.

1st
zeroth
3rd
none of these

Answer 13

zeroth

Question 14

No work is done by the system, when a reaction occurs at constant

volume
temperature
pressure
none of these

Answer 14

volume

Question 15

If the vapour pressure at two temperatures of a solid phase in equilibrium with its liquid phase are known, then the latent heat of fusion can be calculated by the

Maxwell’s equation
Clayperon-Claussius equation
Van Laar equation
Nernst Heat Theorem

Answer 15

Clayperon-Claussius equation

Question 16

“At the absolute zero temperature, the entropy of every perfectly crystalline substance becomes zero”. This follows from the

third law of thermodynamics
second law of thermodynamics
Nernst heat theorem
Maxwell’s relations

Answer 16

third law of thermodynamics

Question 17

During Joule-Thomson expansion of gases

enthalpy remains constant.
entropy remains constant.
temperature remains constant.
none of these.

Answer 17

enthalpy remains constant.

Question 18

Degrees of freedom at triple point will be

0
1
2
3

Answer 18

0

Question 19

“Law of corresponding states” says that

A) two different gases behave similarly, if their reduced properties (i.e. P, V and T) are same.
B) the surface of separation (i. e. the meniscus) between liquid and vapour phase disappears at the critical temperature.
C) no gas can be liquified above the critical temperature, howsoever high the pressure may be.
D) the molar heat of energy of gas at constant volume should be nearly constant (about 3 calories).

Answer 19

A) two different gases behave similarly, if their reduced properties (i.e. P, V and T) are same.

Question 20

Linde gas liquefaction process employs cooling

by throttling
by expansion in an engine
at constant pressure
none of these

Answer 20

by throttling

Question 21

1st law of thermodynamics is nothing but the law of conservation of

momentum
mass
energy
none of these

Answer 21

energy

Question 22

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

Answer 22

Carnot cycle

Question 23

Which of the following is a thermodynamic property of a system ?

Concentration
Mass
Temperature
Entropy

Answer 23

Entropy

Question 24

Equilibrium constant decreases as the temperature

increases, for an exothermic reaction.
decreases, for an exothermic reaction.
increases, for an endothermic reaction.
none of these.

Answer 24

increases, for an exothermic reaction.

Question 25

All gases during throttling process at atmospheric temperature and pressure show a cooling effect except

CO2
H2
O2
N2

Answer 25

H2

Question 26

Compressibility factor for almost all the gases are approximately same at the same

pressure and temperature.
reduced pressure and reduced temperature.
critical pressure and critical temperature.
none of these.

Answer 26

reduced pressure and reduced temperature.

Question 27

In jet refrigerators, the refrigerating fluid is practically always

water
ammonia
freon
brine

Answer 27

water

Question 28

Water on heating from 1 to 4°C

contracts
expands
has same volume
may contract or expand

Answer 28

contracts