The point at which all the three (solid, liquid and gas) phases co-exist, is known as the __________ point.
Freezing
Triple
Boiling
Boyle
Correct Answer :
B. Triple
Related Questions
In the equation, PVn = constant, if the value of n is in between 1 and y (i.e. Cp/Cv), then it represents a reversible __________ process.
Isometric
Polytropic
Isentropic
Isobaric
Dryness fraction of wet steam is defined as the ratio of mass of vapour in the mixture to the mass of mixture __________ calorimeter is not used for measuring the dryness fraction of steam.
Bomb
Separating
Bucket
Throttling
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
__________ increases with increase in pressure.
The melting point of wax
The boiling point of a liquid
Both (A) and (B)
Neither (A) nor (B)
Which one is true for a throttling process?
A gas may have more than one inversion temperatures
The inversion temperature is different for different gases
The inversion temperature is same for all gases
The inversion temperature is the temperature at which Joule-Thomson co-efficient is infinity
__________ Equation predicts the activity coefficient from experimental data.
Lewis-Randall
Margules
Van Laar
Both (B) & (C)
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
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)
The equation, Cp - Cv = R, is true for __________ gas.
No
Any real
Only ideal
Both (B) and (C)
Vapour which is at a pressure smaller than the saturation pressure for the temperature involved is called a __________ vapour.
Superheated
Desuperheated
Non-condensable
None of these
In an irreversible process
Tds = dE - dW = 0
dE - dW - Tds = 0
Tds - dE + dW < 0
Tds - dT + dW < 0
Entropy change for an irreversible isolated system is
∞
0
< 0
> 0
The expression for the work done for a reversible polytropic process can be used to obtain the expression for work done for all processes, except reversible __________ process.
Isobaric
Isothermal
Adiabatic
None of these
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
Law of corresponding states says that
Two different gases behave similarly, if their reduced properties (i.e. P, V and T) are same
The surface of separation (i. e. the meniscus) between liquid and vapour phase disappears at the critical temperature
No gas can be liquefied above the critical temperature, howsoever high the pressure may be.
The molar heat of energy of gas at constant volume should be nearly constant (about 3 calories)
Steam undergoes isentropic expansion in a turbine from 5000 kPa and 400°C (entropy = 6.65 kJ/kg K) to 150 kPa) (entropy of saturated liquid = 1.4336 kJ/kg. K, entropy of saturated vapour = 7.2234 kJ/kg. K) The exit condition of steam is
Superheated vapour
Partially condensed vapour with quality of 0.9
Saturated vapour
Partially condensed vapour with quality of 0.1
Chemical potential (an intensive property) of a substance is a force that drives the chemical system to equilibrium and is equal to its partial molar properties. The ratio of chemical potential to free energy of a pure substance at constant temperature and pressure is
0
1
∞
None of these
Fugacity and pressure are numerically not equal for the gases
At low temperature and high pressure
At standard state
Both (A) and (B)
In ideal state
In an ideal refrigeration cycle, the change in internal energy of the fluid is
+ve
-ve
0
Either of the above three; depends on the nature of refrigerant
What is the value of maximum COP in case of absorption refrigeration, if refrigeration provided is at temperature, TR (where, T1 and T2 are source & surrounding temperatures respectively.)?
TR/(T2 - TR) × (T1 - T2)/T1
TR/(T2 - TR) × T1/(T1 - T2)
TR/(T1 - TR) × (T1 - T2)/T1
None of these
Joule-Thomson co-efficient for a perfect gas is
Zero
Positive
Negative
None of these
A change in state involving a decrease in entropy can be spontaneous, only if
It is exothermic
It is isenthalpic
It takes place isothermally
It takes place at constant volume
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
Pick out the correct statement:
In an isothermal system, irreversible work is more than reversible work
Under reversible conditions, the adiabatic work is less than isothermal work
Heat, work, enthalpy and entropy are all 'state functions'
Matter and energy cannot be exchanged with the surroundings in a closed system
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
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)
Specific __________ does not change during phase change at constant temperature and pressure.
Entropy
Gibbs energy
Internal energy
Enthalpy
The standard state of a gas (at a given temperature) is the state in which fugacity is equal to
Unity
Activity
Both (A) & (B)
Neither (A) nor (B)
During Joule-Thomson expansion of gases
Enthalpy remains constant
Entropy remains constant
Temperature remains constant
None of these
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