In any spontaneous process, the __________ free energy decreases.
Helmholtz
Gibbs
Both a & b
Neither 'a' nor 'b'
Correct Answer :
C. Both a & b
Related Questions
For a single component two phase mixture, the number of independent variable properties are
Two
One
Zero
Three
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
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
Gibbs free energy (F) is defined as
F = E - TS
F = H - TS
F = H + TS
F = E + TS
The expression, nRT ln(P1/P2), is for the __________of an ideal gas.
Compressibility
Work done under adiabatic condition
Work done under isothermal condition
Co-efficient of thermal expansion
The co-efficient of performance (COP) of a refrigerating system, which is its index of performance, is defined as the ratio of useful refrigeration to the net work. The units of __________ and COP are the same.
Kinematic viscosity
Work
Temperature
None of these
For equilibrium process (i.e. reversible) in an isolated system
ds = 0
ds < 0
ds > 0
ds = Constant
No work is done by the system, when a reaction occurs at constant
Volume
Temperature
Pressure
None of these
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 compressibility factor for an ideal gas is 1. Its value for any other real gas is
1
< 1
> 1
Either (B) or (C), depends on the nature of the gas
The unit of fugacity is the same as that of the
Pressure
Temperature
Volume
Molar concentration
As the time is passing, entropy of the universe
Is increasing
Is decreasing
Remain constant
Data insufficient, can't be predicted
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
What is the number of degree of freedom for a system of two miscible non-reacting species in vapor-liquid equilibrium forming an azeotrope?
0
2
1
3
For a constant volume process
dE = CpdT
dE = CvdT
dQ = dE + pdV
dW = pdV
For spontaneous changes in an isolated system (S = entropy)
ds = 0
ds <0
ds > 0
ds = Constant
__________ law of thermodynamics ascertains the direction of a particular spontaneous process.
Zeroth
First
Second
Third
Lenz's law results from the law of conservation of
Mass
Momentum
Energy
None of these
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)
Translational kinetic energy of molecules of an ideal gas is proportional to (where, T = absolute temperature of the gas)
T
√T
T2
1/√T
A system in which there is exchange of energy but not of mass, is called a/an __________ system.
Isolated
Open
Insulated
Closed
In Joule-Thomson porous plug experiment, the
Enthalpy does not remain constant
Entire apparatus is exposed to surroundings
Temperature remains constant
None of these
4 kg moles of an ideal gas expands in vacuum spontaneously. The work done is
4 J
∞
0
8 J
Domestic refrigerator usually works on the __________ refrigeration cycle.
Carnot
Air
Absorption
vapour-ejection
Helmholtz free energy (A) is defined as
A = H - TS
A = E - TS
A = H + TS
None of these
In case of an __________ process, the temperature of the system increases.
Isothermal compression
Isothermal expansion
Adiabatic expansion
Adiabatic compression
In the decomposition of PCl5 represented by, PCl5 PCl3 + Cl2, decrease in the pressure of the system will __________ the degree of dissociation of PCl5.
Increase
Decrease
Not alter
None of these
In an irreversible process
Tds = dE - dW = 0
dE - dW - Tds = 0
Tds - dE + dW < 0
Tds - dT + dW < 0
When a system is in equilibrium for all possible processes, the differential or finite change of entropy is
< 0
> 0
= 0
None of these
Isentropic process means a constant __________ process.
Enthalpy
Pressure
Entropy
None of these