Throttling process is a/an __________ process.
Reversible and isothermal
Irreversible and constant enthalpy
Reversible and constant entropy
Reversible and constant enthalpy
Correct Answer :
B. Irreversible and constant enthalpy
Related Questions
Which of the following is not an extensive property?
Free energy
Entropy
Refractive index
None of these
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
For a multi-component system, the term chemical potential is equivalent to the
Molal concentration difference
Molar free energy
Partial molar free energy
Molar free energy change
In case of vapour compression refrigeration system, elevating the evaporator temperature (keeping the condenser temperature constant) results in
Enhanced COP
Decreased COP
No change in the value of COP
Increased or decreased COP; depending upon the type of refrigerant
Gibbs free energy of a pure fluid approaches __________ as the pressure tends to zero at constant temperature.
Infinity
Minus infinity
Zero
None of these
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
Specific __________ does not change during phase change at constant temperature and pressure.
Entropy
Gibbs energy
Internal energy
Enthalpy
The minimum number of phases that can exist in a system is
0
1
2
3
The expression, nRT ln(P1/P2), is for the __________of an ideal gas.
Compressibility
Work done under adiabatic condition
Work done under isothermal condition
Co-efficient of thermal expansion
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
Specific/molar Gibbs free energy for a pure substance does not change during
Sublimation
Vaporisation
Melting
Either (A), (B) or (C)
In which of the following reaction equilibrium, the value of equilibrium constant Kp will be more than is Kc?
2HI H2 + I2
N2O4 2NO2
2SO2 + O2 2SO3
None of these
A cylinder contains 640 gm of liquid oxygen. The volume occupied (in litres) by the oxygen, when it is released and brought to standard conditions (0°C, 760 mm Hg) will be __________ litres.
448
224
22.4
Data insufficient; can't be computed
Dryness fraction of wet steam is defined as the ratio of mass of vapour in the mixture to the mass of mixture __________ calorimeter is not used for measuring the dryness fraction of steam.
Bomb
Separating
Bucket
Throttling
Entropy is a measure of the __________ of a system.
Disorder
Orderly behaviour
Temperature changes only
None of these
In the equation, PVn = constant, if the value of n is in between 1 and y (i.e. Cp/Cv), then it represents a reversible __________ process.
Isometric
Polytropic
Isentropic
Isobaric
The variation of heat of reaction with temperature at constant pressure is given by the __________ law.
Kelvin's
Antoines
Kirchoffs
None of these
What is the degree of freedom for a system comprising liquid water equilibrium with its vapour?
0
1
2
3
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
When pressure is applied on the system, ice ↔ water, then
Equilibrium cannot be established
More ice will be formed
More water will be formed
Evaporation of water will take place
Isobaric process means a constant process.
Temperature
Pressure
Volume
Entropy
Which of the following is not a reversible process?
Expansion of an ideal gas against constant pressure
Atmospheric pressure vaporisation of water at 100°C
Solution of NaCl in water at 50°C
None of these
Maxwell's relation corresponding to the identity, dH = dS = Vdp + Σμi dni is
(∂T/∂V)S, ni = -(∂P/∂S)V, ni
(∂S/∂P)T, ni = (∂V/∂T)P, ni
(∂S/∂V)T, ni = (∂P/∂T)V, ni
(∂T/∂P)S, ni = (∂V/∂S)P, ni
Gibbs free energy per mole for a pure substance is equal to the
Latent heat of vaporisation
Chemical potential
Molal boiling point
Heat capacity
__________ law of thermodynamics ascertains the direction of a particular spontaneous process.
Zeroth
First
Second
Third
An isolated system can exchange __________ with its surroundings.
Matter
Energy
Neither matter nor energy
Both matter and energy
The expression, ΔG = nRT. ln(P2/P1), gives the free energy change
With pressure changes at constant temperature
Under reversible isothermal volume change
During heating of an ideal gas
During cooling of an ideal gas
Entropy change of the reaction, H2O (liquid) → H2O (gas), is termed as the enthalpy of
Solution
Vaporisation
Formation
Sublimation
In the equation, PVn = Constant, if the value of n = 0, then it represents a reversible __________ process.
Isobaric
Isothermal
Isentropic
Isometric
When a gas in a vessel expands, its internal energy decreases. The process involved is
Reversible
Irreversible
Isothermal
Adiabatic