At normal boiling point, molar entropy of vaporisation is __________ Joule/K°.mole.
72
92
142
192
Correct Answer :
B. 92
Related Questions
A gas has a volume of 27.3 c.c. at 0°C. Its volume at 10°C (if pressure remains unchanged) will be __________ c.c.
2.73
28.3
273
283
Joule-Thomson co-efficient for a perfect gas is
Zero
Positive
Negative
None of these
Heat is added at constant temperature in an ideal __________ cycle.
Stirling
Brayton
Rankine
None of these
Specific/molar Gibbs free energy for a pure substance does not change during
Sublimation
Vaporisation
Melting
Either (A), (B) or (C)
Which of the following behaves most closely like an ideal gas?
He
N2
O2
H2
At constant temperature and pressure, for one mole of a pure substance, the ratio of the free energy to the chemical potential is
Zero
One
Infinity
Negative
What is the number of degree of freedom for a system of two miscible non-reacting species in vapor-liquid equilibrium forming an azeotrope?
0
2
1
3
Entropy change for an irreversible process taking system and surrounding together is
0
> 0
< 0
None of these
The amount of heat required to decompose a compound into its elements is __________ the heat of formation of that compound from its elements.
Less than
More than
Same as
Not related to
The unit of equilibrium constant of a chemical reaction is the same as that of
Molar concentration
Temperature
Internal energy
None of these
Grams of butane (C4H10) formed by the liquefaction of 448 litres of the gas (measured at (STP) would be
580
640
1160
Data insufficient; can't be computed
Which of the following represents the Virial equation of state?
T = [RT/(V- b)] - [a/√T. V(V + b)]
PV/RT = 1 + (B/V) + (C/V2) + ……
n1u2 + μ2μ1 = 0
None of these
What is the ratio of adiabatic compressibility to isothermal compressibility?
1
< 1
> 1
>> 1
Mollier diagram is a plot of
Temperature vs. enthalpy
Temperature vs. enthalpy
Entropy vs. enthalpy
Temperature vs. internal energy
All gases above its inversion temperature, in a throttling process will show
A heating effect
No change in temperature
A cooling effect
Either (A) or (C)
Pressure-enthalpy chart is useful in refrigeration. The change in internal energy of an ideal fluid used in ideal refrigeration cycle is
Positive
Negative
Zero
Infinity
Internal energy of an element at 1 atm and 25° C is __________ kcal/kg.mole.
0
273
25
None of these
A Carnot cycle consists of the following steps:
Two isothermal and two isentropic
Two isobaric and two isothermal
Two isochoric and two isobaric
Two isothermals and two isochoric
The equilibrium constant for a chemical reaction at two different temperatures is given by
Kp2/Kp1 = - (ΔH/R) (1/T2 - 1/T1)
Kp2/Kp1 = (ΔH/R) (1/T2 - 1/T1)
Kp2/Kp1 = ΔH (1/T2 - 1/T1)
Kp2/Kp1 = - (1/R) (1/T2 - 1/T1)
For an ideal liquid solution, which of the following is unity?
Activity
Fugacity
Activity co-efficient
Fugacity co-efficient
As the temperature is lowered towards the absolute zero, the value of ∂(ΔF)/∂T, then approaches
Unity
Zero
That of the heat of reaction
Infinity
All gases except __________ shows a cooling effect during throttling process at atmospheric temperature and pressure.
Oxygen
Nitrogen
Air
Hydrogen
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
The Joule-Thomson co-efficient is defined as (∂T/∂P)H. Its value at the inversion point is
∞
1
0
-ve
Pick out the wrong statement.
A refrigeration cycle violates the second law of thermodynamics
Refrigeration cycle is normally represented by a temperature vs. entropy plot
In a refrigerator, work required decreases as the temperature of the refrigerator and the temperature at which heat is rejected increases
One ton of refrigeration is equivalent to the rate of heat absorption equal to 3.53 kW
Co-efficient of Performance (COP) of a refrigerator is the ratio of the
Work required to refrigeration obtained
Refrigeration obtained to the work required
Lower to higher temperature
Higher to lower temperature
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
The point at which all the three (solid, liquid and gas) phases co-exist, is known as the __________ point.
Freezing
Triple
Boiling
Boyle
Joule-Thomson co-efficient is defined as
μ = (∂P/∂T)H
μ = (∂T/∂P)H
μ = (∂E/∂T)H
μ = (∂E/∂P)H
The following heat engine produces power of 100,000 kW. The heat engine operates between 800 K and 300 K. It has a thermal efficiency equal to 50% of that of the Carnot engine for the same temperature. The rate at which heat is absorbed from the hot reservoir is
100,000 kW
160,000 kW
200,000 kW
320,000 kW