When a gas is subjected to adiabatic expansion, it gets cooled due to
Decrease in velocity
Decrease in temperature
Decrease in kinetic energy
Energy spent in doing work
Correct Answer :
D. Energy spent in doing work
Related Questions
Degrees of freedom at triple point will be
0
1
2
3
A chemical reaction will occur spontaneously at constant pressure and temperature, if the free energy is
Zero
Positive
Negative
None of these
Forward reaction will be favoured for the exothermic reaction, represented by CO + H2O CO2 + H2, by
Low temperature and high pressure
Low temperature and low pressure
High temperature and high pressure
High temperature and low pressure
Which of the following is not an intensive property?
Molar heat capacity
Internal energy
Viscosity
None of these
Enthalpy of a gas depends upon its
Temperature
Mass
Volume
Pressure
In the reaction, C + O2 → CO2; ΔH = - 94 kcal. What is the heat content (enthalpy) of O2?
-94 kcal
> -94 kcal
< - 94 kcal
Zero
In which of the following reaction equilibrium, the value of equilibrium constant Kp will be more than is Kc?
2HI H2 + I2
N2O4 2NO2
2SO2 + O2 2SO3
None of these
Claude gas liquefaction process employs cooling
At constant pressure
By throttling
By expansion in an engine
None of these
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
Claude's liquefaction process employs the cooling of gases by
Expansion in an engine
Following a constant pressure cycle
Throttling
None of these
Pick out the Clausius-Clapeyron equation from the following:
dP/dT = ΔH/TΔV
ln P = - (ΔH/RT) + constant
ΔF = ΔH + T [∂(ΔF)/∂T]P
None of these
In the equation PVn = constant, if the value of n = y = Cp/Cv, then it represents a reversible __________ process.
Isothermal
Adiabatic
Isentropic
Polytropic
A system in which there is exchange of energy but not of mass, is called a/an __________ system.
Isolated
Open
Insulated
Closed
Which is not a refrigerant?
SO2
NH3
CCl2F2
C2H4Cl2
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
Requisites of a reversible process is that the
System and surroundings pressure be equal
Friction in the system should be absent
System and surroundings temperature be equal
None of these
If different processes are used to bring about the same chemical reaction, the enthalpy change is same for all of them. This is __________ law.
Hess's
Kirchoff's
Lavoisier and Laplace
None of these
Heat evolved/absorbed during conversion of a substance from one allotropic form to another is termed as the heat of
Fusion
Vaporisation
Transition
None of these
In case of vapour compression refrigeration system, elevating the evaporator temperature (keeping the condenser temperature constant) results in
Enhanced COP
Decreased COP
No change in the value of COP
Increased or decreased COP; depending upon the type of refrigerant
The point at which all the three (solid, liquid and gas) phases co-exist, is known as the __________ point.
Freezing
Triple
Boiling
Boyle
Which of the following is an undesirable characteristic of a refrigerant?
It should be non-explosive
It should have a sub-atmospheric vapor pressure at the temperature in refrigerator coils
Its vapor pressure at the condenser temperature should be very high
None of these
Isobaric process means a constant process.
Temperature
Pressure
Volume
Entropy
The unit of fugacity is the same as that of the
Pressure
Temperature
Volume
Molar concentration
It is desired to bring about a certain change in the state of a system by performing work on the system under adiabatic conditions.
The amount of work needed is path dependent
Work alone cannot bring out such a change of state
The amount of work needed is independent of path
More information is needed to conclude anything about the path dependence or otherwise of the work needed
The number of degrees of freedom at the triple point of water is
0
1
2
3
Entropy change of the reaction, H2O (liquid) → H2O (gas), is termed as the enthalpy of
Solution
Vaporisation
Formation
Sublimation
The internal energy of an incompressible fluid depends upon its
Pressure
Temperature
Both (A) & (B)
Neither (A) nor (B)
Specific volume of an ideal gas is
Equal to its density
The reciprocal of its density
Proportional to pressure
None of these
Which of the following is not an extensive property?
Free energy
Entropy
Refractive index
None of these
Thermal efficiency of a Carnot engine can approach 100%, only when the temperature of the
Cold reservoir approaches zero
Hot reservoir approaches infinity
Either (A) or (B)
Neither (A) nor (B)