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
Correct Answer :
A. Less than
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
Compressibility factor (i.e., the ratio of actual volume of gas to the volume predicted by ideal gas law) for all gases are
Always greater than one
Same at the same reduced temperature
Same at the same reduced pressure
Both (B) & (C)
For any system, what is the minimum number of degrees of freedom?
0
1
2
3
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
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
Boyle's law for gases states that
P ∝ 1/V, when temperature is constant
P ∝ 1/V, when temperature & mass of the gas remain constant
P ∝ V, at constant temperature & mass of the gas
P/V = constant, for any gas
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
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 kinetic energy of gas molecule is zero at
0°C
273°C
100°C
-273°C
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)
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
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)
Which of the following equations is obtained on combining 1st and 2nd law of thermodynamics, for a system of constant mass?
dE = Tds - PdV
dQ = CvdT + PdV
dQ = CpdT + Vdp
Tds = dE - PdV
Refrigeration capacity of a household refrigerator may be round about __________ tons.
0.15
1.5
4.5
6.5
Linde gas liquefaction process employs cooling
By throttling
By expansion in an engine
At constant pressure
None of these
Internal energy change of a system over one complete cycle in a cyclic process is
Zero
+ve
-ve
Dependent on the path
Mollier diagram is a plot of
Temperature vs. enthalpy
Temperature vs. enthalpy
Entropy vs. enthalpy
Temperature vs. internal energy
The effect of changing the evaporator temperature on COP as compared to that of changing the condenser temperature (in vapour compression refrigeration system) is
Less pronounced
More pronounced
Equal
Data insufficient, can't be predicted
Chemical potential is a/an
Extensive property
Intensive property
Force which drives the chemical system to equilibrium
Both (B) and (C)
Melting of wax is accompanied with __________ in entropy.
Increase
Decrease
No change
None of these
The number of degrees of freedom for a mixture of ice and water (liquid) are
3
2
1
0
Work done may be calculated by the expression ∫ p dA for __________ processes.
Non-flow reversible
Adiabatic
Both (A) and (B)
Neither (A) nor (B)
For multi-component multiple phases to be in equilibrium at the same pressure and temperature, the __________ of each component must be same in all phases.
Chemical potential
Fugacity
Both (A) and (B)
Neither (A) nor (B)
Activity co-efficient is a measure of the
Departure from ideal solution behaviour
Departure of gas phase from ideal gas law
Vapour pressure of liquid
None of these
For a given substance at a specified temperature, activity is __________ to fugacity.
Directly proportional
Inversely proportional
Equal
None of these
For a constant pressure reversible process, the enthalpy change (ΔH) of the system is
Cv.dT
Cp.dT
∫ Cp.dT
∫ Cv.dT
Internal energy of an ideal gas
Increases with increase in pressure
Decreases with increase in temperature
Is independent of temperature
None of these
A gas can be liquefied by pressure alone only, when its temperature is __________ its critical temperature.
Less than
More than
Equal to or higher than
Less than or equal to
For an isothermal process, the internal energy of a gas
Increases
Decreases
Remains unchanged
Data insufficient, can't be predicted
For a single component two phase mixture, the number of independent variable properties are
Two
One
Zero
Three