Throttling (Joule-Thomson effect) process is a constant __________ process.
Enthalpy
Entropy
Pressure
None of these
Correct Answer :
A. Enthalpy
Related Questions
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
If the molar heat capacities (Cp or Cv) of the reactants and products of a chemical reaction are identical, then, with the increase in temperature, the heat of reaction will
Increase
Decrease
Remain unaltered
Increase or decrease; depends on the particular reaction
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
Pick out the undesirable property for a good refrigerant.
High thermal conductivity
Low freezing point
Large latent heat of vaporisation
High viscosity
dW and dq are not the exact differential, because q and W are
State functions
Path functions
Intensive properties
Extensive properties
An ideal gas is taken around the cycle ABCA as shown in P-V diagram below: The work done by the gas during the cycle is equal to
12 P1V1
6 P1 V1
3 P1V1
P1 V1
One mole of nitrogen at 8 bar and 600 K is contained in a piston-cylinder arrangement. It is brought to 1 bar isothermally against a resisting pressure of 1 bar. The work done (in Joules) by the gas is
30554
10373
4988.4
4364.9
What is the degree of freedom for a system comprising liquid water equilibrium with its vapour?
0
1
2
3
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
Entropy is a/an
State function
Macroscopic property
Extensive property
None of these
Solubility of a substance which dissolves with an increase in volume and liberation of heat will be favoured by the
Low pressure and high temperature
Low pressure and low temperature
High pressure and low temperature
High pressure and high temperature
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)
Van Laar equation deals with the activity coefficients in
Binary solutions
Ternary solutions
Azeotropic mixture only
None of these
Which of the following non-flow reversible compression processes require maximum work?
Adiabatic process
Isothermal process
Isobaric process
All require same work
With increase in temperature, the atomic heat capacities of all solid elements
Increases
Decreases
Remains unchanged
Decreases linearly
Molar heat capacity of water in equilibrium with ice at constant pressure is __________ Kcal/kg mole. °K
0
∞
50
100
The value of Joule-Thomson co-efficient, in case where cooling occurs after the throttling process is
0
∞
+ve
-ve
Pick out the wrong statement.
The conversion for a gas phase reaction increases with decrease in pressure, if there is an increase in volume accompanying the reaction
With increase in temperature, the equilibrium constant increases for an exothermic reaction
The equilibrium constant of a reaction depends upon temperature only
The conversion for a gas phase reaction increases with increase in pressure, if there is a decrease in volume accompanying the reaction
Claude gas liquefaction process employs cooling
At constant pressure
By throttling
By expansion in an engine
None of these
Compound having large heat of formation is
More stable
Less stable
Not at all stable (like nascent O2)
Either more or less stable; depends on the compound
Joule-Thomson co-efficient for a perfect gas is
Zero
Positive
Negative
None of these
Efficiency of a heat engine working on Carnot cycle between two temperature levels depends upon the
Two temperatures only
Pressure of working fluid
Mass of the working fluid
Mass and pressure both of the working fluid
The Joule-Thomson co-efficient is defined as (∂T/∂P)H. Its value at the inversion point is
∞
1
0
-ve
Fugacity and pressure are numerically not equal for the gases
At low temperature and high pressure
At standard state
Both (A) and (B)
In ideal state
A gas mixture of three components is brought in contact with a dispersion of an organic phase in water. The degree of freedom of the system is
3
4
5
6
Linde gas liquefaction process employs cooling
By throttling
By expansion in an engine
At constant pressure
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)
Throttling process is a/an __________ process.
Reversible and isothermal
Irreversible and constant enthalpy
Reversible and constant entropy
Reversible and constant enthalpy
Which of the following is Clausius-Clapeyron Equation for vaporisation of an ideal gas under the condition that the molar volume of liquid is negligible compared to that of the vapor?
d ln p/dt = Hvap/RT2
d ln p/dt = RT2/Hvap
dp/dt = RT2/Hvap
dp/dt = Hvap/RT2
Steam undergoes isentropic expansion in a turbine from 5000 kPa and 400°C (entropy = 6.65 kJ/kg K) to 150 kPa) (entropy of saturated liquid = 1.4336 kJ/kg. K, entropy of saturated vapour = 7.2234 kJ/kg. K) The exit condition of steam is
Superheated vapour
Partially condensed vapour with quality of 0.9
Saturated vapour
Partially condensed vapour with quality of 0.1