An ideal gas is taken around the cycle ABCA as shown in P-V diagram below: The work done by the gas during the cycle is equal to
12 P1V1
6 P1 V1
3 P1V1
P1 V1
Correct Answer :
C. 3 P1V1
Related Questions
The variation of heat of reaction with temperature at constant pressure is given by the __________ law.
Kelvin's
Antoines
Kirchoffs
None of these
When liquid and vapour phases of one component system are in equilibrium (at a given temperature and pressure), the molar free energy is
More in vapour phase
More in liquid phase
Same in both the phases
Replaced by chemical potential which is more in vapour phase
Generation of heat by friction is an example of a/an __________ change.
Isothermal
Irreversible
Adiabatic
Reversible
For an ideal solution, the value of activity co-efficient is
0
1
< 1
> 1
A reasonably general expression for vapourliquid phase equilibrium at low to moderate pressure is φi yi P = Yi xifi° where, Φ is a vapor fugacity component, Yi is the liquid activity co-efficient and fi° is the fugacity of the pure component i. the Ki value (Yi = Ki xi) is therefore, in general a function of
Temperature only
Temperature and pressure only
Temperature, pressure and liquid composition xi only
Temperature, pressure, liquid composition xi and vapour composition yi
y = specific heat ratio of an ideal gas is equal to
Cp/Cv
Cp/(CP-R)
1 + (R/CV)
All (A), (B) and (C)
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 has the minimum value of COP for a given refrigeration effect?
Reverse Carnot cycle
Ordinary vapour-compression cycle
Vapour-compression process with a reversible expansion engine
Air refrigeration cycle
A refrigeration cycle is the same as a __________ cycle,
Turbine
Heat engine
Reversed heat engine
None of these
No work is done by the system, when a reaction occurs at constant
Volume
Temperature
Pressure
None of these
The main feature of Carnot refrigeration cycle is that, it
Does not need the addition of external work for its functioning
Transfers heat from high temperature to low temperature
Accomplishes the reverse effect of the heat engine
None of these
Entropy of an ideal gas depends upon its
Pressure
Temperature
Both (A) & (B)
Neither (A) nor (B)
One ton of refrigeration capacity is equivalent to the heat removal rate of
50 kcal/hr
200 BTU/hr
200 BTU/minute
200 BTU/day
A cylinder contains 640 gm of liquid oxygen. The volume occupied (in litres) by the oxygen, when it is released and brought to standard conditions (0°C, 760 mm Hg) will be __________ litres.
448
224
22.4
Data insufficient; can't be computed
In the equation PVn = constant, if the value of n = y = Cp/Cv, then it represents a reversible __________ process.
Isothermal
Adiabatic
Isentropic
Polytropic
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
A refrigerator works on the principle of __________ law of thermodynamics.
Zeroth
First
Second
Third
A two stage compressor is used to compress an ideal gas. The gas is cooled to the initial temperature after each stage. The intermediate pressure for the minimum total work requirement should be equal to the __________ mean of P1 and P2. (where, P1 and P2 are initial and final pressures respectively)
Logarithmic
Arithmetic
Geometric
Harmonic
In an isothermal process on an ideal gas, the pressure increases by 0.5 percent. The volume decreases by about __________ percent.
0.25
0.5
0.75
1
The shape of T-S diagram for Carnot Cycle is a
Rectangle
Rhombus
Trapezoid
Circle
Which of the following is Virial equation of state?
(p + a/V2)(V - b) = nRT
PV = nRT
PV = A + B/V + C/V2 + D/V3 + ...
None of these
The principle applied in liquefaction of gases is
Adiabatic expansion
Joule-Thomson effect
Both (A) and (B)
Neither (A) nor (B)
If the heat of solution of an ideal gas in a liquid is negative, then its solubility at a given partial pressure varies with the temperature as
Solubility increases as temperature increases
Solubility increases as temperature decreases
Solubility is independent of temperature
Solubility increases or decreases with temperature depending on the Gibbs free energy change of solution
Critical temperature is defined as the temperature above which a gas will
Not liquify (barring exceptions)
Immediately liquify
Never liquify however high the pressure may be
None of these
Equilibrium constant of a reaction varies with the
Initial concentration of the reactant
Pressure
Temperature
None of these
The theoretical minimum work required to separate one mole of a liquid mixture at 1 atm, containing 50 mole % each of n- heptane and noctane into pure compounds each at 1 atm is
-2 RT ln 0.5
-RT ln 0.5
0.5 RT
2 RT
There is a change in __________ during the phase transition.
Volume
Pressure
Temperature
All a, b & c
The freezing point of a liquid decreases when the pressure is increased, if the liquid __________ while freezing.
Contracts
Expands
Does not change in volume
Either (A), (B) or (C)
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
Which of the following units is not present in both the vapor compression refrigeration system and absorption refrigeration system?
Expansion valve
Condenser
Refrigerator
Compressor