Pick out the correct statement.
The available energy in an isolated system for all irreversible (real) processes decreases
The efficiency of a Carnot engine increases, if the sink temperature is decreased
The reversible work for compression in non-flow process under isothermal condition is the change in Helmholtz free energy
All (A), (B) and (C)
Correct Answer :
D. All (A), (B) and (C)
Related Questions
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
Number of components (C), phase (P) and degrees of freedom (F) are related by Gibbs phase rule as
P + F - C = 2
C = P - F + 2
F = C - P - 2
P = F - C - 2
Joule-Thomson co-efficient is defined as
μ = (∂P/∂T)H
μ = (∂T/∂P)H
μ = (∂E/∂T)H
μ = (∂E/∂P)H
In a reversible chemical reaction (where, Δx = number of moles of products-number of moles of reactants)
Addition of inert gas favours the forward reaction, when Δx is positive
Pressure has no effect on equilibrium, when Δn = 0
Addition of inert gas has no effect on the equilibrium constant at constant volume for any value of Δx (+ ve, - ve) or zero)
All 'a', 'b' & 'c'
For an ideal liquid solution, which of the following is unity?
Activity
Fugacity
Activity co-efficient
Fugacity co-efficient
The unity of Planck's constant 'h' in the equation, E = hv is
J/s
J.S
J/kmol
kmol/J
Co-efficient of performance for a reversed Carnot cycle working between temperatures T1 and T2 (T1 > T2) is
T2/(T1 - T2)
T1/(T1 - T2)
(T1 - T2)/T1
(T1 - T2)/T2
The necessary condition for phase equilibrium in a multiphase system of N components is that the
Chemical potentials of a given component should be equal in all phases
Chemical potentials of all components should be same in a particular phase
Sum of the chemical potentials of any given component in all the phases should be the same
None of these
Equilibrium constant of a reaction varies with the
Initial concentration of the reactant
Pressure
Temperature
None of these
Partial molar free energy of an element A in solution is same as its
Chemical potential
Activity
Fugacity
Activity co-efficient
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
Which of the following is an undesirable characteristic of a refrigerant?
It should be non-explosive
It should have a sub-atmospheric vapor pressure at the temperature in refrigerator coils
Its vapor pressure at the condenser temperature should be very high
None of these
When a gas is subjected to adiabatic expansion, it gets cooled due to
Decrease in velocity
Decrease in temperature
Decrease in kinetic energy
Energy spent in doing work
The temperature at the eutectic point of the system is the __________ temperature that can be attained in the system.
Lowest
Highest
Average
None of these
Boiling of liquid is accompanied with increase in the
Vapor pressure
Specific Gibbs free energy
Specific entropy
All (A), (B) and (C)
Isentropic process means a constant __________ process.
Enthalpy
Pressure
Entropy
None of these
Fugacity and pressure are numerically not equal for the gases
At low temperature and high pressure
At standard state
Both (A) and (B)
In ideal state
If different processes are used to bring about the same chemical reaction, the enthalpy change is same for all of them. This is __________ law.
Hess's
Kirchoff's
Lavoisier and Laplace
None of these
In case of an __________ process, the temperature of the system increases.
Isothermal compression
Isothermal expansion
Adiabatic expansion
Adiabatic compression
The intensive properties are
Molar volume, density, viscosity and boiling point
Refractive index and surface tension
Both (A) and (B)
None of these
If we increase the pressure on a substance (which is at its triple point), then the triple point
Increases
Decreases
Remains unchanged
May increase or decrease; depends on the substance
Pick out the correct statement.
A real gas on expansion in vacuum gets heated up
An ideal gas on expansion in vacuum gets cooled
An ideal gas on expansion in vacuum gets heated up
A real gas on expansion in vacuum cools down whereas ideal gas remains unaffected
A refrigerator works on the principle of __________ law of thermodynamics.
Zeroth
First
Second
Third
Adiabatic compression of a saturated water vapour makes it
Supersaturated
Superheated
Both (A) and (B)
Neither (A) nor (B)
The first law of thermodynamics is a statement of conservation of
Heat
Momentum
Energy
Work
The reaction A (l) → R(g) is allowed to reach equilibrium conditions in an autoclave. At equilibrium, there are two phases, one a pure liquid phase of A and the other a vapor phase of A, R and S. Initially A alone is present. The numbers of degrees of freedom are:
1
2
3
0
Gibbs-Duhem equation relates composition in liquid phase and the __________ at constant temperature & pressure.
Fugacity
Partial pressure
Activity co-efficient
All (A), (B), and (C)
High __________ is an undesirable property for a good refrigerant.
Specific heat
Latent heat of vaporisation
Viscosity
Specific vapor volume
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)
Grams of butane (C4H10) formed by the liquefaction of 448 litres of the gas (measured at (STP) would be
580
640
1160
Data insufficient; can't be computed