The unity of Planck's constant 'h' in the equation, E = hv is
J/s
J.S
J/kmol
kmol/J
Correct Answer :
B. J.S
Related Questions
Third law of thermodynamics is concerned with the
Value of absolute entropy
Energy transfer
Direction of energy transfer
None of these
For a real gas, the chemical potential is given by
RT d ln P
RT d ln f
R d ln f
None of these
Fundamental principle of refrigeration is based on the __________ law of thermodynamics.
Zeroth
First
Second
Third
For an ideal gas, the activity co-efficient is
Directly proportional to pressure
Inversely proportional to pressure
Unity at all pressures
None of these
In a P-V diagram (for an ideal gas), an isothermal curve will coincide within adiabatic curve (through a point), when
Cp < Cv
Cp = Cv
Cp > Cv
C ≥ Cv
One mole of nitrogen at 8 bar and 600 K is contained in a piston-cylinder arrangement. It is brought to 1 bar isothermally against a resisting pressure of 1 bar. The work done (in Joules) by the gas is
30554
10373
4988.4
4364.9
Mollier chart is a __________ plot.
Pressure vs. enthalpy
Pressure vs. volume
Enthalpy vs. entropy
Temperature vs. entropy
__________ Equation predicts the activity coefficient from experimental data.
Lewis-Randall
Margules
Van Laar
Both (B) & (C)
The most important application of distribution law is in
Evaporation
Liquid extraction
Drying
Distillation
Adiabatic compression of a saturated water vapour makes it
Supersaturated
Superheated
Both (A) and (B)
Neither (A) nor (B)
In case of a reversible process (following pvn = constant), work obtained for trebling the volume (v1 = 1 m3 and v23 m3) is maximum, when the value of 'n' is
0
1
y = 1.44
1.66
Mollier diagram is a plot of
Temperature vs. enthalpy
Temperature vs. enthalpy
Entropy vs. enthalpy
Temperature vs. internal energy
The equation, PV = nRT, is best obeyed by gases at
Low pressure & high temperature
High pressure & low temperature
Low pressure & low temperature
None of these
Number of degrees of freedom for a three phase system in equilibrium comprising of three nonreacting chemical species is
2
0
1
3
Pick out the wrong statement pertaining to the decomposition of PCl5 represented by, PCl5 PCl3 + Cl2.Degree of dissociation of PCl5 will
Decrease on addition of Cl2
Increase on addition of an inert gas at constant pressure
Decrease on increasing the pressure of the system
None of these
(1/V) (∂V/∂T)P is the mathematical expression
Joule-Thomson co-efficient
Specific heat at constant pressure (Cp)
co-efficient of thermal expansion
Specific heat at constant volume (CV)
The number of degree of freedom for an Azeotropic mixture of ethanol and water in vapourliquid equilibrium, is
3
1
2
0
The work done in an adiabatic change in a particular gas depends upon changes in the __________ only.
Temperature
Specific heat
Volume
Pressure
Cp of a gas at its critical temperature and pressure
Becomes zero
Becomes infinity
Equals 1 kcal/kmol °K
Equals 0.24 kcal/kmol °K
Co-efficient of Performance (COP) of a refrigerator is the ratio of the
Work required to refrigeration obtained
Refrigeration obtained to the work required
Lower to higher temperature
Higher to lower temperature
Gibbs free energy of a pure fluid approaches __________ as the pressure tends to zero at constant temperature.
Infinity
Minus infinity
Zero
None of these
At the critical point of a substance
The surface tension vanishes
Liquid and vapour have the same density
There is no distinction between liquid and vapour phases
All (A), (B) and (C)
PVy = constant, holds good for an isentropic process, which is
Reversible and isothermal
Isothermal and irreversible
Reversible and adiabatic
Adiabatic and irreversible
For water at 300°C, it has a vapour pressure 8592.7 kPa and fugacity 6738.9 kPa Under these conditions, one mole of water in liquid phase has a volume of 25.28 cm3 and that in vapour phase in 391.1 cm3.Fugacity of water (in kPa) at 9000 kPa will be
6738.9
6753.5
7058.3
9000
Pick out the correct statement.
If an insoluble gas is passed through a volatile liquid placed in a perfectly insulated container, the temperature of the liquid will increase
A process is irreversible as long as Δ S for the system is greater than zero
The mechanical work done by a system is always equal to∫P.dV
The heat of formation of a compound is defined as the heat of reaction leading to the formation of the compound from its reactants
Which of the following decreases with increase in pressure?
Melting point of ice
Melting point of wax
Boiling point of liquids
None of these
Compressibility factor-reduced pressure plot on reduced co-ordinates facilitates
Use of only one graph for all gases
Covering of wide range
Easier plotting
More accurate plotting
Generation of heat by friction is an example of a/an __________ change.
Isothermal
Irreversible
Adiabatic
Reversible
The compressibility factor for an ideal gas is 1. Its value for any other real gas is
1
< 1
> 1
Either (B) or (C), depends on the nature of the gas
At equilibrium condition, the chemical potential of a material in different phases in contact with each other is equal. The chemical potential for a real gas (μ) is given by (where, μ = standard chemical potential at unit fugacity (f° = 1 atm.) and the gas behaves ideally.)
μ° + RT ln f
μ°+ R ln f
μ° + T ln f
μ° + R/T ln f