The temperature at which a real gas obeys the ideal gas laws over a wide range of pressure is called the __________ temperature.
Critical
Boyle
Inversion
Reduced
Correct Answer :
B. Boyle
Related Questions
Partial molar free energy of an element A in solution is same as its
Chemical potential
Activity
Fugacity
Activity co-efficient
Gibbs free energy (G) is represented by, G = H - TS, whereas Helmholtz free energy, (A) is given by, A = E - TS. Which of the following is the Gibbs-Helmholtz equation?
[∂(G/T)/∂T] = - (H/T2)
[∂(A/T)/∂T]V = - E/T2
Both (A) and (B)
Neither (A) nor (B)
The first law of thermodynamics is a restatement of the law of conservation of
Mass
Energy
Momentum
None of these
If the pressure on 100 c.c. of air is halved, then its volume (at the same temperature) would be __________ c.c.
100
50
205
200
A reasonably general expression for vapourliquid phase equilibrium at low to moderate pressure is φi yi P = Yi xifi° where, Φ is a vapor fugacity component, Yi is the liquid activity co-efficient and fi° is the fugacity of the pure component i. the Ki value (Yi = Ki xi) is therefore, in general a function of
Temperature only
Temperature and pressure only
Temperature, pressure and liquid composition xi only
Temperature, pressure, liquid composition xi and vapour composition yi
In reactions involving solids and liquids (where change in volume is negligible), the heat of reaction at constant pressure as compared to that at constant volume is
More
Less
Same
Unpredictable; depends on the particular reaction
For an ideal gas, the activity co-efficient is
Directly proportional to pressure
Inversely proportional to pressure
Unity at all pressures
None of these
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
For an ideal liquid solution, which of the following is unity?
Activity
Fugacity
Activity co-efficient
Fugacity co-efficient
At equilibrium condition, the chemical potential of a material in different phases in contact with each other is equal. The chemical potential for a real gas (μ) is given by (where, μ = standard chemical potential at unit fugacity (f° = 1 atm.) and the gas behaves ideally.)
μ° + RT ln f
μ°+ R ln f
μ° + T ln f
μ° + R/T ln f
The standard Gibbs free energy change of a reaction depends on the equilibrium
Pressure
Temperature
Composition
All (A), (B) and (C)
The partial pressure of each constituent present in an alloy is __________ the total vapor pressure exerted by the alloy.
Less than
Equal to
More than
Either (B) or (C); depends on the type of alloy
After throttling, gas temperature
Decreases
Increases
Remain same
May increase or decrease; depends on the nature of the gas
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
Which of the following processes cannot be made reversible even under ideal condition of operation?
Free expansion of a gas
Compression of air in a compressor
Expansion of steam in a turbine
All (A), (B) & (C)
The change in Gibbs free energy for vaporisation of a pure substance is
Positive
Negative
Zero
May be positive or negative
When pressure is applied on the system, ice ↔ water, then
Equilibrium cannot be established
More ice will be formed
More water will be formed
Evaporation of water will take place
The chemical potential of any constituent of an ideal solution depends on the __________ of the solution.
Temperature
Pressure
Composition
All (A), (B) and (C)
Which of the following is not a common refrigerant?
Freon-12
Ethylene
Ammonia
Carbon dioxide
Gases are cooled in Joule-Thomson expansion, when it is __________ inversion temperature.
Below
At
Above
Either 'b' or 'c'
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
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
Forward reaction will be favoured for the exothermic reaction, represented by CO + H2O CO2 + H2, by
Low temperature and high pressure
Low temperature and low pressure
High temperature and high pressure
High temperature and low pressure
During the phase transition, __________ changes.
Pressure
Volume
Temperature
All (A), (B) and (C)
Mollier chart is a __________ plot.
Pressure vs. enthalpy
Pressure vs. volume
Enthalpy vs. entropy
Temperature vs. entropy
Fugacity of a component in an ideal gas mixture is equal to the partial pressure of that component in the mixture. The fugacity of each component in a stable homogeneous solution at constant pressure and temperature __________ as its mole fraction increases.
Decreases
Decreases exponentially
Increases
Remain constant
For an isothermal process, the internal energy of a gas
Increases
Decreases
Remains unchanged
Data insufficient, can't be predicted
The internal energy of an incompressible fluid depends upon its
Pressure
Temperature
Both (A) & (B)
Neither (A) nor (B)
Normal temperature and pressure (N.T.P.) corresponds to
0°C and 760 mm Hg
15°C and 760 mm Hg
20°C and 760 mm Hg
0°C and 1 kgf/cm2
The point at which all the three (solid, liquid and gas) phases co-exist, is known as the __________ point.
Freezing
Triple
Boiling
Boyle