Linde gas liquefaction process employs cooling
By throttling
By expansion in an engine
At constant pressure
None of these
Correct Answer :
A. By throttling
Related Questions
After throttling, gas temperature
Decreases
Increases
Remain same
May increase or decrease; depends on the nature of the gas
Which of the following behaves most closely like an ideal gas?
He
N2
O2
H2
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 expression for entropy change given by, ΔS = nR ln (V2/V1) + nCv ln (T2/T1) is valid for
Reversible isothermal volume change
Heating of a substance
Cooling of a substance
Simultaneous heating and expansion of an ideal gas
Fugacity and pressure are numerically equal, when the gas is
In standard state
At high pressure
At low temperature
In ideal state
Cv for an ideal gas
Does not depend upon temperature
Is independent of pressure only
Is independent of volume only
Is independent of both pressure and volume
The point at which all the three (solid, liquid and gas) phases co-exist, is known as the __________ point.
Freezing
Triple
Boiling
Boyle
Law of corresponding states says that
Two different gases behave similarly, if their reduced properties (i.e. P, V and T) are same
The surface of separation (i. e. the meniscus) between liquid and vapour phase disappears at the critical temperature
No gas can be liquefied above the critical temperature, howsoever high the pressure may be.
The molar heat of energy of gas at constant volume should be nearly constant (about 3 calories)
Pick out the wrong statement.
The chemical potential of a pure substance depends upon the temperature and pressure
The chemical potential of a component in a system is directly proportional to the escaping tendency of that component
The chemical potential of ith species (μi) in an ideal gas mixture approaches zero as the pressure or mole fraction (xi) tends to be zero at constant temperature
The chemical potential of species 'i' in the mixture (μi) is mathematically represented as,μi = ∂(nG)/∂ni]T,P,nj where, n, ni and nj respectively denote the total number of moles, moles of ith species and all mole numbers except ith species. 'G' is Gibbs molar free energy
For a thermodynamic system containing 'x' chemical species, the maximum number of phases that can co-exist at equilibrium is
x
x + 1
x + 2
x + 3
In case of the decomposition of hydroiodic acid (2HI H2 + I2), addition of H2 (at equilibrium condition) will
Increase the partial pressure of I2
Decrease the partial pressure of HI
Diminish the degree of dissociation of HI
None of these
The free energy change for a chemical reaction is given by (where, K = equilibrium constant)
RT ln K
-RT ln K
-R ln K
T ln K
Heat pump
Accomplishes only space heating in winter
Accomplishes only space cooling in summer
Accomplishes both (A) and (B)
Works on Carnot cycle
If the internal energy of an ideal gas decreases by the same amount as the work done by the system, then the
Process must be isobaric
Temperature must decrease
Process must be adiabatic
Both (B) and (C)
In a P-V diagram (for an ideal gas), an isothermal curve will coincide within adiabatic curve (through a point), when
Cp < Cv
Cp = Cv
Cp > Cv
C ≥ Cv
__________ decreases during adiabatic throttling of a perfect gas.
Entropy
Temperature
Enthalpy
Pressure
For an ideal solution, the value of activity co-efficient is
0
1
< 1
> 1
At the critical point of a substance
The surface tension vanishes
Liquid and vapour have the same density
There is no distinction between liquid and vapour phases
All (A), (B) and (C)
What is the degree of freedom for two miscible (non-reacting) substances in vapor-liquid equilibrium forming an azeotrope?
0
1
2
3
Clausius-Clapeyron equation is applicable to __________ equilibrium processes.
Solid-vapor
Solid-liquid
Liquid-vapor
All (A), (B) and (C)
If the vapour pressure at two temperatures of a solid phase in equilibrium with its liquid phase are known, then the latent heat of fusion can be calculated by the
Maxwell's equation
Clausius-Clapeyron Equation
Van Laar equation
Nernst Heat Theorem
An isolated system can exchange __________ with its surroundings.
Matter
Energy
Neither matter nor energy
Both matter and energy
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
The relation connecting the fugacities of various components in a solution with one another and to composition at constant temperature and pressure is called the __________ equation.
Gibbs-Duhem
Van Laar
Gibbs-Helmholtz
Margules
In case of a reversible process (following pvn = constant), work obtained for trebling the volume (v1 = 1 m3 and v23 m3) is maximum, when the value of 'n' is
0
1
y = 1.44
1.66
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)
As the time is passing, entropy of the universe
Is increasing
Is decreasing
Remain constant
Data insufficient, can't be predicted
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 the reaction, H2 +I2 2HI, addition of an inert gas will
Increase the partial pressure of H2
Increase the partial pressure of I2
Increase the total pressure and hence shift the equilibrium towards the right
Not affect the equilibrium conditions
The unit of fugacity is the same as that of the
Pressure
Temperature
Volume
Molar concentration