As the temperature is lowered towards the absolute zero, the value of the quantity (∂ΔF/∂T) approaches
Zero
Unity
Infinity
None of these
Correct Answer :
A. Zero
Related Questions
The efficiency of an Otto engine compared to that of a diesel engine, for the same compression ratio will be
More
Less
Same
Data insufficient to predict
Air enters an adiabatic compressor at 300K. The exit temperature for a compression ratio of 3, assuming air to be an ideal gas (Y = Cp/Cv = 7/5) and the process to be reversible, is
300 × (32/7)
300 × (33/5)
300 × (333/7)
300 × (35/7)
In the reaction, H2 +I2 2HI, addition of an inert gas will
Increase the partial pressure of H2
Increase the partial pressure of I2
Increase the total pressure and hence shift the equilibrium towards the right
Not affect the equilibrium conditions
COP of a refrigerator drawing 1 kW of power per ton of refrigeration is about
0.5
3.5
4.5
8.5
When a system in equilibrium is subjected to a change in temperature, pressure or concentration, the equilibrium is displaced in a direction which tends to undo the effect of the change. This is called the
Le-Chatelier principle
Kopp's rule
Law of corresponding state
Arrhenius hypothesis
Air-refrigeration cycle
Is the most efficient of all refrigeration cycles
Has very low efficiency
Requires relatively large quantities of air to achieve a significant amount of refrigeration
Both (B) and (C)
Van Laar equation deals with the activity coefficients in
Binary solutions
Ternary solutions
Azeotropic mixture only
None of these
Melting of ice exemplifies a/an
Adiabatic process
Endothermic reaction
Exothermic reaction
Process involving a chemical reaction
__________ decreases during adiabatic throttling of a perfect gas.
Entropy
Temperature
Enthalpy
Pressure
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
For an ideal liquid solution, which of the following is unity?
Activity
Fugacity
Activity co-efficient
Fugacity co-efficient
Work done in case of free expansion is
Indeterminate
Zero
Negative
None of these
First law of thermodynamics is mathematically stated as
dQ = dE + dW
dQ = dE - dW
dE = dQ + dW
dW = dQ + dE
__________ increases with increase in pressure.
The melting point of wax
The boiling point of a liquid
Both (A) and (B)
Neither (A) nor (B)
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
No work is done by the system, when a reaction occurs at constant
Volume
Temperature
Pressure
None of these
Internal energy is equal to the heat absorbed in case of a/an __________ process.
Constant volume
Polytropic
Adiabatic
Constant pressure
In case of a close thermodynamic system, there is __________ across the boundaries.
No heat and mass transfer
No mass transfer but heat transfer
Mass and energy transfer
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
1m3 of an ideal gas at 500 K and 1000 kPa expands reversibly to 5 times its initial volume in an insulated container. If the specific heat capacity (at constant pressure) of the gas is 21 J/mole . K, the final temperature will be
35 K
174 K
274 K
154 K
The quantitative effect of temperature on chemical equilibrium is given by the
Vant-Hoff equation
Le-Chatelier's principle
Arrhenius equation
None of these
A cyclic engine exchanges heat with two reservoirs maintained at 100 and 300°C respectively. The maximum work (in J) that can be obtained from 1000 J of heat extracted from the hot reservoir is
349
651
667
1000
If two pure liquid constituents are mixed in any proportion to give an ideal solution, there is no change in
Volume
Enthalpy
Both (A) & (B)
Neither (A) nor (B)
While dissolving a gas into a liquid at a constant temperature, the ratio of the concentration of the gas in the solution phase and in the gaseous phase is
Infinity
Unity
Constant
Negative
When a gas is expanded from high pressure region to low pressure region; temperature change occurs. This phenomenon is related to the
Gibbs-Duhem equation
Gibbs-Helmholtz equation
Third law of thermodynamics
Joule-Thomson effect
Which of the following is not correct for a reversible adiabatic process?
TVγ-1 = constant
p1-γ.TY = constant
PVγ = constant
None of these
dW and dq are not the exact differential, because q and W are
State functions
Path functions
Intensive properties
Extensive properties
The minimum number of phases that can exist in a system is
0
1
2
3
The standard state of a gas (at a given temperature) is the state in which fugacity is equal to
Unity
Activity
Both (A) & (B)
Neither (A) nor (B)
High __________ is an undesirable property for a good refrigerant.
Specific heat
Latent heat of vaporisation
Viscosity
Specific vapor volume