INDIABIX-CHE THERMODYNAMICS Flashcards
Maximum work that could be secured by expanding the gas over a given pressure range is the __________ work.
isothermal
adiabatic
isentropic
none of these
isothermal
Internal energy change of a system over one complete cycle in a cyclic process is
zero
+ve
-ve
dependent on the path
zero
Heating of water under atmospheric pressure is an __________ process.
isochoric
isobaric
adiabatic
isothermal
isobaric
Van Laar equation deals with the activity co-efficients in
binary solutions
ternary solutions
azeotropic mixture only
none of these
binary solutions
High __________ is an undesirable property for a good refrigerant.
specific heat
latent heat of vaporisation
viscosity
specific vapor volume
viscosity
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.
low pressure and low temperature.
A chemical reaction will occur spontaneously at constant pressure and temperature, if the free energy is
zero
positive
negative
none of these
negative
Fundamental principle of refrigeration is based on the __________ law of thermodynamics.
zeroth
first
second
third
second
For a spontaneous process, free energy
is zero
increases
decreases whereas the entropy increases
and entropy both decrease
decreases whereas the entropy increases
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.
Carnot refrigeration cycle.
In a working refrigerator, the value of COP is always
0
< 0
< 1
> 1
> 1
A refrigerator may be termed as a
heat pump
heat engine
Carnot engine
none of these
heat pump
Measurement of thermodynamic property of temperature is facilitated by __________ law of thermodynamics.
1st
zeroth
3rd
none of these
zeroth
No work is done by the system, when a reaction occurs at constant
volume
temperature
pressure
none of these
volume
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
Clayperon-Claussius equation
“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
third law of thermodynamics
During Joule-Thomson expansion of gases
enthalpy remains constant.
entropy remains constant.
temperature remains constant.
none of these.
enthalpy remains constant.
Degrees of freedom at triple point will be
0
1
2
3
0
“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).
A) two different gases behave similarly, if their reduced properties (i.e. P, V and T) are same.
Linde gas liquefaction process employs cooling
by throttling
by expansion in an engine
at constant pressure
none of these
by throttling
1st law of thermodynamics is nothing but the law of conservation of
momentum
mass
energy
none of these
energy
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
Carnot cycle
Which of the following is a thermodynamic property of a system ?
Concentration
Mass
Temperature
Entropy
Entropy
Equilibrium constant decreases as the temperature
increases, for an exothermic reaction.
decreases, for an exothermic reaction.
increases, for an endothermic reaction.
none of these.
increases, for an exothermic reaction.
All gases during throttling process at atmospheric temperature and pressure show a cooling effect except
CO2
H2
O2
N2
H2
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.
reduced pressure and reduced temperature.
In jet refrigerators, the refrigerating fluid is practically always
water
ammonia
freon
brine
water
Water on heating from 1 to 4°C
contracts
expands
has same volume
may contract or expand
contracts
