Which of the following will increase the volume of a real gas by four times?
Doubling the absolute temperature as well as pressure of the gas
Reducing pressure to one fourth at constant temperature
Reducing temperature to one fourth at constant pressure
Reducing the temperature to half and doubling the pressure
Correct Answer :
B. Reducing pressure to one fourth at constant temperature
Related Questions
After throttling, gas temperature
Decreases
Increases
Remain same
May increase or decrease; depends on the nature of the gas
In case of a close thermodynamic system, there is __________ across the boundaries.
No heat and mass transfer
No mass transfer but heat transfer
Mass and energy transfer
None of these
The main feature of Carnot refrigeration cycle is that, it
Does not need the addition of external work for its functioning
Transfers heat from high temperature to low temperature
Accomplishes the reverse effect of the heat engine
None of these
All gases except __________ shows a cooling effect during throttling process at atmospheric temperature and pressure.
Oxygen
Nitrogen
Air
Hydrogen
The number of degrees of freedom for an azeotropic mixture in a two component vapour-liquid equilibria is/are
Zero
One
Two
Three
There is a change in __________ during the phase transition.
Volume
Pressure
Temperature
All a, b & c
PVγ = Constant (where, γ = Cp/Cv) is valid for a/an __________ process.
Isothermal
Isentropic
Isobaric
Adiabatic
Pick out the correct statement.
A real gas on expansion in vacuum gets heated up
An ideal gas on expansion in vacuum gets cooled
An ideal gas on expansion in vacuum gets heated up
A real gas on expansion in vacuum cools down whereas ideal gas remains unaffected
An isolated system can exchange __________ with its surroundings.
Matter
Energy
Neither matter nor energy
Both matter and energy
Free energy, fugacity and activity co-efficient are all affected by change in the temperature. The fugacity co-efficient of a gas at constant pressure ____with the increase of reduced temperature.
Decreases
Increases
Remains constant
Decreases logarithmically
Dry ice is
Moisture free ice
Solid helium
Solid carbon dioxide
None of these
If atmospheric temperature and dew point are nearly equal, then the relative humidity is
Zero
50%
Almost 100%
unpredictable
The temperature at which a real gas obeys the ideal gas laws over a wide range of pressure is called __________ temperature.
Boyle
Inversion
Critical
Reduced
Entropy of a substance remains constant during a/an __________ change.
Reversible isothermal
Irreversible isothermal
Reversible adiabatic
None of these
Refrigeration cycle
Violates second law of thermodynamics
Involves transfer of heat from low temperature to high temperature
Both (A) and (B)
Neither (A) nor (B)
The equation relating E, P, V and T which is true for all substances under all conditions is given by (∂E/∂V)T = T(∂P/∂T)H - P. This equation is called the
Maxwell's equation
Thermodynamic equation of state
Equation of state
Redlich-Kwong equation of state
A refrigerator may be termed as a
Heat pump
Heat engine
Carnot engine
None of these
High pressure steam is expanded adiabatically and reversibly through a well insulated turbine, which produces some shaft work. If the enthalpy change and entropy change across the turbine are represented by ΔH and ΔS respectively for this process:
Δ H = 0 and ΔS = 0
Δ H ≠ 0 and ΔS = 0
Δ H ≠ 0 and ΔS ≠ 0
Δ H = 0 and ΔS ≠ 0
The standard state of a gas (at a given temperature) is the state in which fugacity is equal to
Unity
Activity
Both (A) & (B)
Neither (A) nor (B)
Chemical potential of ith component of a system is given by
μi = (∂F/∂ni)T, P, ni
μi = (∂A/∂ni)T, P, ni
μi = (∂F/∂ni)T, P
μi = (∂A/∂ni)T, P
Melting of ice exemplifies a/an
Adiabatic process
Endothermic reaction
Exothermic reaction
Process involving a chemical reaction
As pressure approaches zero, the ratio of fugacity to pressure (f/P) for a gas approaches
Zero
Unity
Infinity
An indeterminate value
Pick out the wrong statement
Phase rule variables are intensive properties
Heat and work are both state function
The work done by expansion of a gas in vacuum is zero
CP and CV are state function
In an irreversible process
Tds = dE - dW = 0
dE - dW - Tds = 0
Tds - dE + dW < 0
Tds - dT + dW < 0
Which is not a refrigerant?
SO2
NH3
CCl2F2
C2H4Cl2
Free energy change of mixing two liquid substances is a function of the
Concentration of the constituents only
Quantities of the constituents only
Temperature only
All (A), (B) and (C)
What is the value of ln y (where y = activity co-efficient) for ideal gases?
Zero
Unity
Infinity
Negative
Throttling process is a/an __________ process.
Reversible and isothermal
Irreversible and constant enthalpy
Reversible and constant entropy
Reversible and constant enthalpy
Pick out the wrong statement.
Cp of monatomic gases such as metallic vapor is about 5 kcal/kg.atom
The heat capacity of solid inorganic substance is exactly equal to the heat capacity of the substance in the molten state
There is an increase in entropy, when a spontaneous change occurs in an isolated system
At absolute zero temperature, the heat capacity for many pure crystalline substances is zero
Trouton's ratio is given by (where λb, = molal heat of vaporisation of a substance at its normal boiling point, kcal/kmol Tb = normal boiling point, °K)
λb/Tb
Tb/λb
√(λb/Tb)
√(Tb/λb)