Which is not constant for an ideal gas?
(∂P/∂V)T
(∂V/∂T)P
(∂P/∂V)V
All (A), (B) & (C)
Correct Answer :
A. (∂P/∂V)T
Related Questions
Enthalpy 'H' is defined as
H = E - PV
H = F - TS
H - E = PV
None of these
Which of the following behaves most closely like an ideal gas?
He
N2
O2
H2
Joule-Thomson effect i.e., a throttling process is a constant __________ process.
Entropy
Temperature
Internal energy
Enthalpy
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
The heat capacities for the ideal gas state depend upon the
Pressure
Temperature
Both (A) & (B)
Neither (A) nor (B)
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)
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
Pick out the correct statement.
Compression ratio of an Otto engine is comparatively higher than a diesel engine
Efficiency of an Otto engine is higher than that of a diesel engine for the same compression ratio
Otto engine efficiency decreases with the rise in compression ratio, due to decrease in work produced per quantity of heat
Diesel engine normally operates at lower compression ratio than an Otto engine for an equal output of work
For any system, what is the minimum number of degrees of freedom?
0
1
2
3
The internal energy of an ideal gas does not change in a reversible __________ process.
Isothermal
Adiabatic
Isobaric
Isometric
Number of phases in a colloidal system is:
1
2
3
4
For a constant volume process
dE = CpdT
dE = CvdT
dQ = dE + pdV
dW = pdV
Heating of water under atmospheric pressure is an __________ process.
Isochoric
Isobaric
Adiabatic
Isothermal
The Carnot co-efficient of performance (COP) of a domestic air conditioner compared to a household refrigerator is
Less
More
Same
Dependent on climatic conditions
At constant temperature and pressure, for one mole of a pure substance, the ratio of the free energy to the chemical potential is
Zero
One
Infinity
Negative
Trouton's ratio of __________ liquids is calculated using Kistyakowsky equation.
Polar
Non-polar
Both (A) & (B)
Neither (A) nor (B)
Pick out the wrong statement.
Enthalpies of all elements in their standard states are assumed to be zero
Combustion reactions are never endothermic in nature
Heat of reaction at constant volume is equal to the change in internal energy
Clausius-Clapeyron equation is not applicable to melting process
The equation, (d loge PA/d loge xA) = (d loge PA/d loge xB) applicable to a binary solution of components. A and B in equilibrium with their vapors at constant temperature and pressure is called the __________ equation.
Van Laar
Margules
Gibbs-Duhem
Gibbs-Duhem-Margules
Pick out the undesirable property for a good refrigerant.
High thermal conductivity
Low freezing point
Large latent heat of vaporisation
High viscosity
Partial molar free energy of an element A in solution is same as its
Chemical potential
Activity
Fugacity
Activity co-efficient
Specific __________ does not change during phase change at constant temperature and pressure.
Entropy
Gibbs energy
Internal energy
Enthalpy
Free energy change at equilibrium is
Zero
Positive
Negative
Indeterminate
The chemical potential of a component (μi) of a phase is the amount by which its capacity for doing all work, barring work of expansion is increased per unit amount of substance added for an infinitesimal addition at constant temperature and pressure. It is given by
(∂E/∂ni)S, v, nj
(∂G/∂ni)T, P, nj = (∂A/∂ni) T, v, nj
(∂H/∂ni)S, P, nj
All (A), (B) and (C)
If the heat of solution of an ideal gas in a liquid is negative, then its solubility at a given partial pressure varies with the temperature as
Solubility increases as temperature increases
Solubility increases as temperature decreases
Solubility is independent of temperature
Solubility increases or decreases with temperature depending on the Gibbs free energy change of solution
The most important application of distribution law is in
Evaporation
Liquid extraction
Drying
Distillation
Which is a state function?
Specific volume
Work
Pressure
Temperature
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
When a system is in equilibrium for all possible processes, the differential or finite change of entropy is
< 0
> 0
= 0
None of these
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
What is the value of ln y (where y = activity co-efficient) for ideal gases?
Zero
Unity
Infinity
Negative