COP of a refrigerator drawing 1 kW of power per ton of refrigeration is about
0.5
3.5
4.5
8.5
Correct Answer :
B. 3.5
Related Questions
Specific heat of a gas for a reversible adiabatic process is
Negative
Zero
Infinity
None of these
Pick out the wrong statement.
A closed system does not permit exchange of mass with its surroundings but may permit exchange of energy.
An open system permits exchange of both mass and energy with its surroundings
The term microstate is used to characterise an individual, whereas macro-state is used to designate a group of micro-states with common characteristics
None of the above
The unity of Planck's constant 'h' in the equation, E = hv is
J/s
J.S
J/kmol
kmol/J
Pick out the wrong statement.
Activity co-efficient is dimensionless.
In case of an ideal gas, the fugacity is equal to its pressure.
In a mixture of ideal gases, the fugacity of a component is equal to the partial pressure of the component.
The fugacity co-efficient is zero for an ideal gas
What is the degree of freedom for a system comprising liquid water equilibrium with its vapour?
0
1
2
3
Joule-Thomson Co-efficient at any point on the inversion curve is
∞
+ve
0
-ve
Heat of reaction at constant volume is identified with __________ change.
Enthalpy
Internal energy
Either (A) or (B)
Neither (A) nor (B)
Measurement of thermodynamic property of temperature is facilitated by __________ law of thermodynamics.
1st
Zeroth
3rd
None of these
Number of degrees of freedom for a three phase system in equilibrium comprising of three nonreacting chemical species is
2
0
1
3
Specific/molar Gibbs free energy for a pure substance does not change during
Sublimation
Vaporisation
Melting
Either (A), (B) or (C)
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)
For an ideal liquid solution, which of the following is unity?
Activity
Fugacity
Activity co-efficient
Fugacity co-efficient
PVy = constant, holds good for an isentropic process, which is
Reversible and isothermal
Isothermal and irreversible
Reversible and adiabatic
Adiabatic and irreversible
Joule-Thomson co-efficient which is defined as, η = (∂T/∂P)H = 1/Cp (∂H/∂T)P, changes sign at a temperature known as inversion temperature. The value of Joule-Thomson co-efficient at inversion temperature is
0
∞
+ve
-ve
Which of the following is not a reversible process?
Expansion of an ideal gas against constant pressure
Atmospheric pressure vaporisation of water at 100°C
Solution of NaCl in water at 50°C
None of these
Cp of a gas at its critical temperature and pressure
Becomes zero
Becomes infinity
Equals 1 kcal/kmol °K
Equals 0.24 kcal/kmol °K
__________ decreases during adiabatic throttling of a perfect gas.
Entropy
Temperature
Enthalpy
Pressure
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
Those solutions in which there is no volume change upon mixing the components in the liquid state and which, when diluted do not undergo any heat change (i.e. heat of dilution is zero), are called __________ solutions.
Ideal
Real
Isotonic
None of these
The four properties of a system viz. P, V, T, S are related by __________ equation.
Gibbs-Duhem
Gibbs-Helmholtz
Maxwell's
None of these
The Carnot co-efficient of performance (COP) of a domestic air conditioner compared to a household refrigerator is
Less
More
Same
Dependent on climatic conditions
Choose the condition that must be specified in order to liquify CO2 (triple point for CO2 is - 57°C and 5.2 atm).
Pressure must be kept below 5.2 atm
Temperature must be kept above - 57°C
Pressure must be kept below 5.2 atm. and temperature must be kept above 57°C
Pressure and temperature must be kept below 5.2 atm. and - 57°C respectively
The first law of thermodynamics is a restatement of the law of conservation of
Mass
Energy
Momentum
None of these
Joule-Thomson experiment is
Isobaric
Adiabatic
Isenthalpic
Both (B) & (C)
For a multi-component system, the term chemical potential is equivalent to the
Molal concentration difference
Molar free energy
Partial molar free energy
Molar free energy change
Entropy is a/an
State function
Macroscopic property
Extensive property
None of these
Which of the following is true for Virial equation of state?
Virial co-efficients are universal constants
Virial co-efficients 'B' represents three body interactions
Virial co-efficients are function of temperature only
For some gases, Virial equations and ideal gas equations are the same
On a P-V diagram of an ideal gas, suppose a reversible adiabatic line intersects a reversible isothermal line at point A. Then at a point A, the slope of the reversible adiabatic line (∂P/∂V)s and the slope of the reversible isothermal line (∂P/ ∂V)T are related as (where, y = Cp/Cv)
(∂P/∂V)S = (∂P/∂V)T
(∂P/∂V)S = [(∂P/∂V)T]Y
(∂P/∂V)S = y(∂P/∂V)T
(∂P/∂V)S = 1/y(∂P/∂V)T
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
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