Which of the following is a widely used refrigerant in vapour compression refrigeration system (using large centrifugal compressor)?
Freon
Liquid sulphur dioxide
Methyl chloride
Ammonia
Correct Answer :
A. Freon
Related Questions
Normal temperature and pressure (N.T.P.) corresponds to
0°C and 760 mm Hg
15°C and 760 mm Hg
20°C and 760 mm Hg
0°C and 1 kgf/cm2
Which of the following is Clausius-Clapeyron Equation for vaporisation of an ideal gas under the condition that the molar volume of liquid is negligible compared to that of the vapor?
d ln p/dt = Hvap/RT2
d ln p/dt = RT2/Hvap
dp/dt = RT2/Hvap
dp/dt = Hvap/RT2
In case of the decomposition of hydroiodic acid (2HI H2 + I2), addition of H2 (at equilibrium condition) will
Increase the partial pressure of I2
Decrease the partial pressure of HI
Diminish the degree of dissociation of HI
None of these
Joule-Thomson co-efficient for a perfect gas is
Zero
Positive
Negative
None of these
Fugacity is a measure of the
Escaping tendencies of the same substance in different phases of a system
Relative volatility of a mixture of two miscible liquids
Behaviour of ideal gases
None of these
At absolute zero temperature, the __________ of the gas is zero.
Pressure
Volume
Mass
None of these
The activity of an ideal gas is numerically __________ its pressure.
More than
Less than
Equal to
Data insufficient, can't be predicted
For a thermodynamic system containing 'x' chemical species, the maximum number of phases that can co-exist at equilibrium is
x
x + 1
x + 2
x + 3
As pressure approaches zero, the ratio of fugacity to pressure (f/P) for a gas approaches
Zero
Unity
Infinity
An indeterminate value
Compressibility factor (i.e., the ratio of actual volume of gas to the volume predicted by ideal gas law) for all gases are
Always greater than one
Same at the same reduced temperature
Same at the same reduced pressure
Both (B) & (C)
Change of state namely evaporation condensation, freezing and melting is an __________ process.
Isothermal
Adiabatic
Isobaric
Isochoric
First law of thermodynamics deals with the
Direction of energy transfer
Reversible processes only
Irreversible processes only
None of these
The equation, Cp - Cv = R, is true for __________ gas.
No
Any real
Only ideal
Both (B) and (C)
In a turbine, the fluid expands almost
Isothermally
Isobarically
Adiabatically
None of these
The adiabatic throttling process of a perfect gas is one of constant enthalpy
In which there is a temperature drop
Which is exemplified by a non-steady flow expansion
Which can be performed in a pipe with a constriction
In which there is an increase in temperature
Which of the following units is not present in both the vapor compression refrigeration system and absorption refrigeration system?
Expansion valve
Condenser
Refrigerator
Compressor
It is desired to bring about a certain change in the state of a system by performing work on the system under adiabatic conditions.
The amount of work needed is path dependent
Work alone cannot bring out such a change of state
The amount of work needed is independent of path
More information is needed to conclude anything about the path dependence or otherwise of the work needed
Pick out the wrong statement.
System (of partially miscible liquid pairs), in which the mutual solubility increases with rise in temperature, are said to possess an upper consolute temperature
Systems, in which the mutual solubility increases with decrease in temperature, are said to possess lower consolute temperature
Nicotine-water system shows both an upper as well as a lower consolute temperature, implying that they are partially miscible between these two limiting temperatures
None of these
An ideal gas is taken around the cycle ABCA as shown in P-V diagram below: The work done by the gas during the cycle is equal to
12 P1V1
6 P1 V1
3 P1V1
P1 V1
A refrigeration cycle is the same as a __________ cycle,
Turbine
Heat engine
Reversed heat engine
None of these
The entropy change in a reversible isothermal process, when an ideal gas expands to four times its initial volume is
R loge 4
R log10 4
Cv log10 4
Cv loge 4
Those solutions in which there is no volume change upon mixing the components in the liquid state and which, when diluted do not undergo any heat change (i.e. heat of dilution is zero), are called __________ solutions.
Ideal
Real
Isotonic
None of these
If atmospheric temperature and dew point are nearly equal, then the relative humidity is
Zero
50%
Almost 100%
unpredictable
__________ Equation predicts the activity coefficient from experimental data.
Lewis-Randall
Margules
Van Laar
Both (B) & (C)
The unit of equilibrium constant of a chemical reaction is the same as that of
Molar concentration
Temperature
Internal energy
None of these
For an exothermic reaction
Only enthalpy change (ΔH) is negative
Only internal energy change (ΔE) is negative
Both ΔH and ΔE are negative
Enthalpy change is zero
Pick out the wrong statement.
Trouton's ratio of non-polar liquids is calculated using Kistyakowsky equation
Thermal efficiency of a Carnot engine is always less than 1
An equation relating pressure, volume and temperature of a gas is called ideal gas equation
None of these
Claude gas liquefaction process employs cooling
At constant pressure
By throttling
By expansion in an engine
None of these
A large iceberg melts at the base, but not at the top, because of the reason that
Ice at the base contains impurities which lowers its melting point
Due to the high pressure at the base, its melting point reduces
The iceberg remains in a warmer condition at the base
All (A), (B) and (C)
Lenz's law results from the law of conservation of
Mass
Momentum
Energy
None of these