The molar excess Gibbs free energy, gE, for a binary liquid mixture at T and P is given by, (gE/RT) = A . x1. x2, where A is a constant. The corresponding equation for ln y1, where y1 is the activity co-efficient of component 1, is
A . x22
Ax1
Ax2
Ax12
Correct Answer :
A. A . x22
Related Questions
For multi-component multiple phases to be in equilibrium at the same pressure and temperature, the __________ of each component must be same in all phases.
Chemical potential
Fugacity
Both (A) and (B)
Neither (A) nor (B)
For a single component two phase mixture, the number of independent variable properties are
Two
One
Zero
Three
The internal energy of an ideal gas does not change in a reversible __________ process.
Isothermal
Adiabatic
Isobaric
Isometric
Chemical potential is a/an
Extensive property
Intensive property
Force which drives the chemical system to equilibrium
Both (B) and (C)
A two stage compressor is used to compress an ideal gas. The gas is cooled to the initial temperature after each stage. The intermediate pressure for the minimum total work requirement should be equal to the __________ mean of P1 and P2. (where, P1 and P2 are initial and final pressures respectively)
Logarithmic
Arithmetic
Geometric
Harmonic
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
The heat capacities for the ideal gas state depend upon the
Pressure
Temperature
Both (A) & (B)
Neither (A) nor (B)
Equation which relates pressure, volume and temperature of a gas is called the
Equation of state
Gibbs Duhem equation
Ideal gas equation
None of these
In the equation, PVn = constant, if the value of n = 1, then it represents a reversible __________ process.
Isothermal
Isobaric
Polytropic
Adiabatic
The specific heat of saturated water vapour at 100°C is
∞
-ve
0
+ve
Cv is given by
(∂E/∂T)V
(∂E/∂V)T
(∂E/∂P)V
(∂V/∂T)P
Ideal gas law is applicable at
Low T, low P
High T, high P
Low T, high P
High T, low P
Requisites of a reversible process is that the
System and surroundings pressure be equal
Friction in the system should be absent
System and surroundings temperature be equal
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
A change in state involving a decrease in entropy can be spontaneous, only if
It is exothermic
It is isenthalpic
It takes place isothermally
It takes place at constant volume
Equilibrium constant decreases as the temperature
Increases, for an exothermic reaction
Decreases, for an exothermic reaction
Increases, for an endothermic reaction
None of these
Extensive properties of a thermodynamic system depend upon the __________ of the system.
Specific volume
Temperature
Mass
Pressure
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)
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
The relation connecting the fugacities of various components in a solution with one another and to composition at constant temperature and pressure is called the __________ equation.
Gibbs-Duhem
Van Laar
Gibbs-Helmholtz
Margules
Specific volume of an ideal gas is
Equal to its density
The reciprocal of its density
Proportional to pressure
None of these
Entropy is a/an
State function
Macroscopic property
Extensive property
None of these
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
In the ammonia synthesis reaction, N2 + 3H2 2NH3 + 22.4 kcal, the formation of NH3 will be favoured by
High temperature
Low pressure
Low temperature only
Both low temperature and high pressure
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
1st law of thermodynamics is nothing but the law of conservation of
Momentum
Mass
Energy
None of these
The internal energy of a gas obeying P (V - b) RT (where, b is a positive constant and has a constant Cv), depends upon its
Pressure
Volume
Temperature
All (A), (B) & (C)
Efficiency of a Carnot engine working between temperatures T1 and T2 (T1 < T) is
(T2 - T1)/T2
(T2 - T1)/T1
(T1 - T2)/T2
(T1 - T2)/T1
The minimum number of phases that can exist in a system is
0
1
2
3
On opening the door of an operating refrigerator kept in a closed room, the temperature of the room will
Increase
Decrease
Remain same
Increase in summer and will decrease in winter