Chemical potential (an intensive property) of a substance is a force that drives the chemical system to equilibrium and is equal to its partial molar properties. The ratio of chemical potential to free energy of a pure substance at constant temperature and pressure is
0
1
∞
None of these
Correct Answer :
B. 1
Related Questions
Which is not constant for an ideal gas?
(∂P/∂V)T
(∂V/∂T)P
(∂P/∂V)V
All (A), (B) & (C)
Work done may be calculated by the expression ∫ p dA for __________ processes.
Non-flow reversible
Adiabatic
Both (A) and (B)
Neither (A) nor (B)
The chemical potential of any constituent of an ideal solution depends on the __________ of the solution.
Temperature
Pressure
Composition
All (A), (B) and (C)
Variation of equilibrium pressure with temperature for any two phases of a given substances is given by the __________ equation.
Gibbs-Duhem
Maxwell's
Clapeyron
None of these
The theoretical minimum work required to separate one mole of a liquid mixture at 1 atm, containing 50 mole % each of n- heptane and noctane into pure compounds each at 1 atm is
-2 RT ln 0.5
-RT ln 0.5
0.5 RT
2 RT
In an ideal solution, the activity of a component equals its
Mole fraction
Fugacity at the same temperature and pressure
Partial pressure
None of these
Domestic refrigerator usually works on the __________ refrigeration cycle.
Carnot
Air
Absorption
vapour-ejection
Pick out the wrong statement.
Surface tension of a substance vanishes at critical point, as there is no distinction between liquid and vapour phases at its critical point
Entropy of a system decreases with the evolution of heat
Change of internal energy is negative for exothermic reactions
The eccentric factor for all materials is always more than one
High __________ is an undesirable property for a good refrigerant.
Specific heat
Latent heat of vaporisation
Viscosity
Specific vapor volume
__________ does not change during phase transformation processes like sublimation, melting & vaporisation.
Entropy
Gibbs free energy
Internal energy
All (A), (B) & (C)
A closed system is cooled reversibly from 100°C to 50°C. If no work is done on the system
its internal energy (U) decreases and its entropy (S) increases
U and S both decreases
U decreases but S is constant
U is constant but S decreases
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)
Enthalpy 'H' is defined as
H = E - PV
H = F - TS
H - E = PV
None of these
During adiabatic expansion of gas
Pressure remains constant
Pressure is increased
Temperature remains constant
None of these
What is the degree of freedom for two miscible (non-reacting) substances in vapor-liquid equilibrium forming an azeotrope?
0
1
2
3
High pressure steam is expanded adiabatically and reversibly through a well insulated turbine, which produces some shaft work. If the enthalpy change and entropy change across the turbine are represented by ΔH and ΔS respectively for this process:
Δ H = 0 and ΔS = 0
Δ H ≠ 0 and ΔS = 0
Δ H ≠ 0 and ΔS ≠ 0
Δ H = 0 and ΔS ≠ 0
Critical compressibility factor for all substances
Are more or less constant (vary from 0.2 to 0.3)
Vary as square of the absolute temperature
Vary as square of the absolute pressure
None of these
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
Entropy change in case of reversible adiabatic process is
Minimum
Zero
Maximum
Indeterminate
The adiabatic throttling process of a perfect gas is one of constant enthalpy
In which there is a temperature drop
Which is exemplified by a non-steady flow expansion
Which can be performed in a pipe with a constriction
In which there is an increase in temperature
Melting of ice is an example of an __________ process.
Adiabatic
Isothermal
Isometric
None of these
The amount of heat required to decompose a compound into its elements is __________ the heat of formation of that compound from its elements.
Less than
More than
Same as
Not related to
Lowering of condenser temperature (keeping the evaporator temperature constant) in case of vapour compression refrigeration system results in
Increased COP
Same COP
Decreased COP
Increased or decreased COP; depending upon the type of refrigerant
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)
Near their critical temperatures, all gases occupy volumes __________ that of the ideal gas.
Less than
Same as
More than
Half
Heating of water under atmospheric pressure is an __________ process.
Isochoric
Isobaric
Adiabatic
Isothermal
Those solutions in which there is no volume change upon mixing the components in the liquid state and which, when diluted do not undergo any heat change (i.e. heat of dilution is zero), are called __________ solutions.
Ideal
Real
Isotonic
None of these
Second law of thermodynamics is concerned with the
Amount of energy transferred
Direction of energy transfer
Irreversible processes only
Non-cyclic processes only
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
One ton of refrigeration capacity is equivalent to the heat removal rate of
50 kcal/hr
200 BTU/hr
200 BTU/minute
200 BTU/day