Second law of thermodynamics is concerned with the
Amount of energy transferred
Direction of energy transfer
Irreversible processes only
Non-cyclic processes only
Correct Answer :
B. Direction of energy transfer
Related Questions
Gibbs-Duhem equation
States that n1dμ1 + n2dμ2 + ....njdμj = 0, for a system of definite composition at constant temperature and pressure
Applies only to binary systems
Finds no application in gas-liquid equilibria involved in distillation
None of these
Free energy
Decreases in all spontaneous (or irreversible) processes
Change during a spontaneous process has a negative value
Remains unchanged in reversible processes carried at constant temperature and pressure
All (A), (B) and (C)
In which of the following reaction equilibrium, the value of equilibrium constant Kp will be more than is Kc?
2HI H2 + I2
N2O4 2NO2
2SO2 + O2 2SO3
None of these
Which is a state function?
Specific volume
Work
Pressure
Temperature
The compressibility factor of a gas is given by (where, V1 = actual volume of the gas V2 = gas volume predicted by ideal gas law)
V1/V2
V2/V1
V1 - V2
V1.V2
Which of the following behaves most closely like an ideal gas?
He
N2
O2
H2
Choose the condition that must be specified in order to liquify CO2 (triple point for CO2 is - 57°C and 5.2 atm).
Pressure must be kept below 5.2 atm
Temperature must be kept above - 57°C
Pressure must be kept below 5.2 atm. and temperature must be kept above 57°C
Pressure and temperature must be kept below 5.2 atm. and - 57°C respectively
Which is not a refrigerant?
SO2
NH3
CCl2F2
C2H4Cl2
Internal energy is equal to the heat absorbed in case of a/an __________ process.
Constant volume
Polytropic
Adiabatic
Constant pressure
Degrees of freedom at triple point will be
0
1
2
3
Throttling (Joule-Thomson effect) process is a constant __________ process.
Enthalpy
Entropy
Pressure
None of these
A system undergoes a change from a given initial state to a given final state either by an irreversible process or by a reversible process, then (where, Δ S1 and Δ SR are the entropy changes of the system for the irreversible and reversible processes respectively)
Δ S1 is always < Δ SR
Δ S1 is sometimes > Δ SR
Δ S1 is always > Δ SR
Δ S1 is always = Δ SR
Degree of freedom of a system consisting of a gaseous mixture of H2 and NH3 will be
0
1
2
3
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
For an exothermic reaction
Only enthalpy change (ΔH) is negative
Only internal energy change (ΔE) is negative
Both ΔH and ΔE are negative
Enthalpy change is zero
At the absolute zero temperature, the entropy of every perfectly crystalline substance becomes zero. This follows from the
Third law of thermodynamics
Second law of thermodynamics
Nernst heat theorem
Maxwell's relations
In case of steady flow compression polytropic process (PVn = constant), the work done on air is the lowest, when
n = y = 1.4
n = 0
n = 1
n = 1.66
In vapour compression refrigeration system, if the evaporator temperature and the condenser temperatures are -13°C and 37°C respectively, the Carnot COP will be
5.2
6.2
0.168
Data insufficient, can't be found out
Cv is given by
(∂E/∂T)V
(∂E/∂V)T
(∂E/∂P)V
(∂V/∂T)P
For an ideal gas, the activity co-efficient is
Directly proportional to pressure
Inversely proportional to pressure
Unity at all pressures
None of these
Equilibrium constant of a reaction varies with the
Initial concentration of the reactant
Pressure
Temperature
None of these
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
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
Degree of freedom of the system ice-watervapour will be
0
1
2
3
For a constant volume process __________ by the system is used only to increase the internal energy.
Heat absorbed
Work done
Both (A) & (B)
Neither (A) nor (B)
Heat of reaction at constant volume is identified with __________ change.
Enthalpy
Internal energy
Either (A) or (B)
Neither (A) nor (B)
Standard temperature and pressure (S.T.P.) is
0°C and 750 mm Hg
15°C and 750 mm Hg
0°C and 1 kgf/cm2
15°C and 1 kgf/cm2
A refrigeration cycle is the same as a __________ cycle,
Turbine
Heat engine
Reversed heat engine
None of these
The internal energy of an ideal gas does not change in a reversible __________ process.
Isothermal
Adiabatic
Isobaric
Isometric
Third law of thermodynamics is concerned with the
Value of absolute entropy
Energy transfer
Direction of energy transfer
None of these