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All questions of Phase Equilibrium for Chemistry Exam
Calculate the eutectic concentration given the following data.
Pressure = 1atm
Temperature: 1oC- a)0
- b)2
- c)1
- d)3
Correct answer is option 'C'. Can you explain this answer?
Calculate the eutectic concentration given the following data.
Pressure = 1atm
Temperature: 1oC
Pressure = 1atm
Temperature: 1oC
a)
0
b)
2
c)
1
d)
3
|
Vivek Khatri answered |
According to Weiss law (which suits only for phase components), concentration at equilibrium is C = T/P. therefore in this case, C = 1/1 = 1. This law is also called as Gibbs relativity law.
A ________ system is one in which no variation of conditions is possible without one phase disappearing.- a)Variant
- b)Invariant
- c)Constant
- d)None of the mentioned
Correct answer is option 'B'. Can you explain this answer?
A ________ system is one in which no variation of conditions is possible without one phase disappearing.
a)
Variant
b)
Invariant
c)
Constant
d)
None of the mentioned
|
|
Vivek Khatri answered |
A invariant system is one in which no variation of conditions is possible without one phase disappearing.
For a pure gas, the values of F, C, and P are
Where: F: Degree of freedom, C: Number of independent component, P: Number of phases that can exist in the system- a)2, 2, 2
- b)2, 2, 1
- c)2, 1, 1
- d)1, 1, 1
Correct answer is option 'C'. Can you explain this answer?
For a pure gas, the values of F, C, and P are
Where: F: Degree of freedom, C: Number of independent component, P: Number of phases that can exist in the system
Where: F: Degree of freedom, C: Number of independent component, P: Number of phases that can exist in the system
a)
2, 2, 2
b)
2, 2, 1
c)
2, 1, 1
d)
1, 1, 1
|
|
Vivek Khatri answered |
F – C + P = 2, for Pure gas, number of phases = 1, and component = 1, then F = 2.
Select the odd statement with respect to a phase reaction.- a)Saturated solution
- b)Equilibrium solution
- c)Concentric solution
- d)Amorphous solution
Correct answer is option 'A'. Can you explain this answer?
Select the odd statement with respect to a phase reaction.
a)
Saturated solution
b)
Equilibrium solution
c)
Concentric solution
d)
Amorphous solution
|
|
Vivek Khatri answered |
A terminal solution, an intermediate solution, an equilibrium solution and concentric solutions, are the ones which take part in a phase reaction. On the other hand, a saturated solution is involved in the Lever system.
Under what condition, will we get a stable phase diagram?- a)Solid + Liquid
- b)Solid + Vapor
- c)Liquid + vapor
- d)Liquid + Solid
Correct answer is option 'A'. Can you explain this answer?
Under what condition, will we get a stable phase diagram?
a)
Solid + Liquid
b)
Solid + Vapor
c)
Liquid + vapor
d)
Liquid + Solid
|
|
Vivek Khatri answered |
According to equilibrium mixture ration, an appropriate ratio of 1:10 parts of solid and liquid along with an aqueous solution will give a stable phase product.
Liquid phase exists for all compositions above _________ region.- a)Eutectic region
- b)Equilibrium region
- c)Isometric region
- d)Sublimation region
Correct answer is option 'C'. Can you explain this answer?
Liquid phase exists for all compositions above _________ region.
a)
Eutectic region
b)
Equilibrium region
c)
Isometric region
d)
Sublimation region
|
Rutuja Choudhary answered |
Liquid phase exists for all compositions above the isometric region.
Explanation:
The liquid phase exists in the phase diagram of a substance at temperatures and pressures where the substance is in a liquid state. The phase diagram is a graphical representation of the various phases (solid, liquid, and gas) that a substance can exist in, at different temperatures and pressures.
The isometric region, also known as the liquid region, is the region in the phase diagram where the substance exists as a liquid. This region is bounded by the melting point curve and the vaporization curve.
- Liquid phase above the eutectic region:
The eutectic region is a specific composition in the phase diagram where a eutectic mixture forms. In this region, the substance undergoes eutectic solidification, which means that it solidifies as a mixture of two or more components. Above the eutectic region, the substance exists in the liquid phase, as it has not reached the composition required for eutectic solidification.
- Liquid phase above the equilibrium region:
The equilibrium region is the region in the phase diagram where the substance exists in equilibrium between the solid and liquid phases. In this region, the substance can exist as a mixture of solid and liquid, depending on the temperature and pressure. Above the equilibrium region, the substance exists in the liquid phase, as it has not reached the conditions for equilibrium between the solid and liquid phases.
- Liquid phase above the sublimation region:
The sublimation region is the region in the phase diagram where the substance undergoes sublimation, which means it directly converts from a solid to a gas phase without passing through the liquid phase. Therefore, the liquid phase does not exist above the sublimation region.
Hence, the correct answer is option C, the liquid phase exists for all compositions above the isometric region.
Explanation:
The liquid phase exists in the phase diagram of a substance at temperatures and pressures where the substance is in a liquid state. The phase diagram is a graphical representation of the various phases (solid, liquid, and gas) that a substance can exist in, at different temperatures and pressures.
The isometric region, also known as the liquid region, is the region in the phase diagram where the substance exists as a liquid. This region is bounded by the melting point curve and the vaporization curve.
- Liquid phase above the eutectic region:
The eutectic region is a specific composition in the phase diagram where a eutectic mixture forms. In this region, the substance undergoes eutectic solidification, which means that it solidifies as a mixture of two or more components. Above the eutectic region, the substance exists in the liquid phase, as it has not reached the composition required for eutectic solidification.
- Liquid phase above the equilibrium region:
The equilibrium region is the region in the phase diagram where the substance exists in equilibrium between the solid and liquid phases. In this region, the substance can exist as a mixture of solid and liquid, depending on the temperature and pressure. Above the equilibrium region, the substance exists in the liquid phase, as it has not reached the conditions for equilibrium between the solid and liquid phases.
- Liquid phase above the sublimation region:
The sublimation region is the region in the phase diagram where the substance undergoes sublimation, which means it directly converts from a solid to a gas phase without passing through the liquid phase. Therefore, the liquid phase does not exist above the sublimation region.
Hence, the correct answer is option C, the liquid phase exists for all compositions above the isometric region.
What is the point at which all the three phases of a system exist?- a)Triple point
- b)Sublimation point
- c)Vapor point
- d)Eutectic point
Correct answer is option 'A'. Can you explain this answer?
What is the point at which all the three phases of a system exist?
a)
Triple point
b)
Sublimation point
c)
Vapor point
d)
Eutectic point
|
Niti Mukherjee answered |
Triple Point
The point at which all three phases of a system coexist is known as the triple point. This is a unique combination of temperature and pressure at which the solid, liquid, and gas phases of a substance can exist in equilibrium.
Explanation
When a substance undergoes a phase change, such as melting or boiling, its physical properties change. These changes depend on the temperature and pressure of the system. The behavior of a substance at different temperature and pressure conditions can be represented on a phase diagram.
A phase diagram is a graphical representation of the different phases of a substance as a function of temperature and pressure. It shows the boundaries between the solid, liquid, and gas phases and the conditions under which phase transitions occur.
At the triple point, the substance exists in equilibrium between its three phases: solid, liquid, and gas. This means that all three phases can coexist at a specific temperature and pressure combination. Any deviation from this point will cause the substance to transition into a different phase.
Importance
The triple point is an important concept in thermodynamics and phase diagrams. It provides a reference point for defining temperature scales and calibrating thermometers. The triple point of water, for example, is used to define the Celsius scale, where 0 degrees Celsius is defined as the temperature at which water's solid, liquid, and gas phases can coexist at a pressure of 611.657 pascals.
Furthermore, the triple point can also be used to determine the purity of a substance. Since the conditions at the triple point are well-defined, any impurities in the substance will cause deviations from the expected temperature and pressure values. Therefore, measuring the triple point of a substance can help determine its purity.
Conclusion
The triple point is the point at which all three phases of a substance can coexist in equilibrium. It is an important concept in thermodynamics and phase diagrams, providing reference points for temperature scales and determining the purity of substances.
The point at which all three phases of a system coexist is known as the triple point. This is a unique combination of temperature and pressure at which the solid, liquid, and gas phases of a substance can exist in equilibrium.
Explanation
When a substance undergoes a phase change, such as melting or boiling, its physical properties change. These changes depend on the temperature and pressure of the system. The behavior of a substance at different temperature and pressure conditions can be represented on a phase diagram.
A phase diagram is a graphical representation of the different phases of a substance as a function of temperature and pressure. It shows the boundaries between the solid, liquid, and gas phases and the conditions under which phase transitions occur.
At the triple point, the substance exists in equilibrium between its three phases: solid, liquid, and gas. This means that all three phases can coexist at a specific temperature and pressure combination. Any deviation from this point will cause the substance to transition into a different phase.
Importance
The triple point is an important concept in thermodynamics and phase diagrams. It provides a reference point for defining temperature scales and calibrating thermometers. The triple point of water, for example, is used to define the Celsius scale, where 0 degrees Celsius is defined as the temperature at which water's solid, liquid, and gas phases can coexist at a pressure of 611.657 pascals.
Furthermore, the triple point can also be used to determine the purity of a substance. Since the conditions at the triple point are well-defined, any impurities in the substance will cause deviations from the expected temperature and pressure values. Therefore, measuring the triple point of a substance can help determine its purity.
Conclusion
The triple point is the point at which all three phases of a substance can coexist in equilibrium. It is an important concept in thermodynamics and phase diagrams, providing reference points for temperature scales and determining the purity of substances.
What does Gibb’s phase rule state?- a)P + F = C - 1
- b)P + F = C + 1
- c)P + F = C - 2
- d)P + F = C + 2
Correct answer is option 'D'. Can you explain this answer?
What does Gibb’s phase rule state?
a)
P + F = C - 1
b)
P + F = C + 1
c)
P + F = C - 2
d)
P + F = C + 2
|
|
Vivek Khatri answered |
The above phase rule is a formula that gives the condition for finding the number of phases in a system. This phase rule can be applied to both condensed as well as normal systems.
Gibbs phase rule is, when no chemical reaction occurs
Where: F: Degree of freedom, C: Number of independent component, P: Number of phases that can exist in the system- a)F – C + P = 2
- b)F + C – P = 2
- c)F + C + P = 2
- d)F – C – P = 2
Correct answer is option 'A'. Can you explain this answer?
Gibbs phase rule is, when no chemical reaction occurs
Where: F: Degree of freedom, C: Number of independent component, P: Number of phases that can exist in the system
Where: F: Degree of freedom, C: Number of independent component, P: Number of phases that can exist in the system
a)
F – C + P = 2
b)
F + C – P = 2
c)
F + C + P = 2
d)
F – C – P = 2
|
|
Vivek Khatri answered |
Gibbs phase rule: F – C + P = 2.
Which of the following is the formula for condense phase rule?- a)F = C - P + 2
- b)F = C - P + 1
- c)F = C + P - 2
- d)F = C + P - 1
Correct answer is option 'B'. Can you explain this answer?
Which of the following is the formula for condense phase rule?
a)
F = C - P + 2
b)
F = C - P + 1
c)
F = C + P - 2
d)
F = C + P - 1
|
Shivam Khanna answered |
Explanation:
The formula for the condensed phase rule is given by option B: F = C - P.
Here's the breakdown of the formula and what each variable represents:
- F: The degrees of freedom, which represents the number of variables that can be varied independently without affecting the number of phases in the system.
- C: The number of components in the system. A component is a chemically independent and distinguishable species that makes up the system. For example, in a mixture of water and ethanol, the two components are water and ethanol.
- P: The number of phases in the system. A phase is a physically distinct and homogeneous part of a system. It can be solid, liquid, or gas. For example, in a system with water and ethanol, if both are present as liquids, there is one liquid phase. But if one of them evaporates and forms a gas phase, there are two phases (liquid and gas).
The condensed phase rule is used to determine the number of variables (degrees of freedom) that can be independently varied in a system while keeping the number of phases constant.
By subtracting the number of phases (P) from the number of components (C), we can determine the degrees of freedom (F). The degrees of freedom represent the number of variables that can be freely adjusted without changing the number of phases in the system.
For example, if we have a system with two components (C = 2) and one phase (P = 1), the formula would be F = 2 - 1 = 1. This means that we have one degree of freedom, and we can vary one variable (such as temperature or pressure) while keeping the system as a single phase.
In summary, the condensed phase rule formula, F = C - P, allows us to determine the degrees of freedom in a system based on the number of components and phases present.
The formula for the condensed phase rule is given by option B: F = C - P.
Here's the breakdown of the formula and what each variable represents:
- F: The degrees of freedom, which represents the number of variables that can be varied independently without affecting the number of phases in the system.
- C: The number of components in the system. A component is a chemically independent and distinguishable species that makes up the system. For example, in a mixture of water and ethanol, the two components are water and ethanol.
- P: The number of phases in the system. A phase is a physically distinct and homogeneous part of a system. It can be solid, liquid, or gas. For example, in a system with water and ethanol, if both are present as liquids, there is one liquid phase. But if one of them evaporates and forms a gas phase, there are two phases (liquid and gas).
The condensed phase rule is used to determine the number of variables (degrees of freedom) that can be independently varied in a system while keeping the number of phases constant.
By subtracting the number of phases (P) from the number of components (C), we can determine the degrees of freedom (F). The degrees of freedom represent the number of variables that can be freely adjusted without changing the number of phases in the system.
For example, if we have a system with two components (C = 2) and one phase (P = 1), the formula would be F = 2 - 1 = 1. This means that we have one degree of freedom, and we can vary one variable (such as temperature or pressure) while keeping the system as a single phase.
In summary, the condensed phase rule formula, F = C - P, allows us to determine the degrees of freedom in a system based on the number of components and phases present.
Select the wrong statements from the following statements with respect to a phase diagram.- a)Gives information about concentration
- b)Gives information about solubility
- c)Gives information on melting and boiling points
- d)Gives information on relative concentration
Correct answer is option 'D'. Can you explain this answer?
Select the wrong statements from the following statements with respect to a phase diagram.
a)
Gives information about concentration
b)
Gives information about solubility
c)
Gives information on melting and boiling points
d)
Gives information on relative concentration
|
|
Vivek Khatri answered |
A phase diagram gives information only on the concentration of species, their solubility rate, degree of freedom and other physical properties. It does not explain about transformation rates and relative concentration (relative concentration=total concentration/equilibrium concentration).
______ variable does depend on how much material you have.- a)Intensive
- b)Extensive
- c)Both intensive and extensive
- d)Neither intensive nor extensive
Correct answer is option 'B'. Can you explain this answer?
______ variable does depend on how much material you have.
a)
Intensive
b)
Extensive
c)
Both intensive and extensive
d)
Neither intensive nor extensive
|
|
Vivek Khatri answered |
Extensive variable does depend on how much material you have.
Select a non-homogeneous system from the following.- a)Salt solution
- b)Sugar solution
- c)Glucose in water
- d)Saturated solution of NaCl
Correct answer is option 'D'. Can you explain this answer?
Select a non-homogeneous system from the following.
a)
Salt solution
b)
Sugar solution
c)
Glucose in water
d)
Saturated solution of NaCl
|
|
Vivek Khatri answered |
A homogeneous mixture is one which is miscible completely with one another. In any saturated solution, when the amount of solute reaches more than a critical point, then the solution becomes heterogeneous.
Properties that do not depend on the quantity of material present, are called- a)Intensive properties
- b)Extensive properties
- c)Variable properties
- d)None of the mentioned
Correct answer is option 'A'. Can you explain this answer?
Properties that do not depend on the quantity of material present, are called
a)
Intensive properties
b)
Extensive properties
c)
Variable properties
d)
None of the mentioned
|
|
Vivek Khatri answered |
Properties that do not depend on the quantity of material present are called intensive properties.
What is the degree of freedom for a mixture of ice and vapour?- a)1
- b)2
- c)3
- d)4
Correct answer is option 'A'. Can you explain this answer?
What is the degree of freedom for a mixture of ice and vapour?
a)
1
b)
2
c)
3
d)
4
|
|
Niharika Choudhary answered |
The degree of freedom for a system refers to the number of variables that can be changed independently without affecting the number of phases or components present in the system. In other words, it represents the number of parameters that can be varied while still maintaining the system in equilibrium.
In the case of a mixture of ice and vapor, we have two phases present: solid (ice) and gas (vapor). The number of components in this system is also two: water and air. To determine the degree of freedom, we need to consider the phase rule, which relates the degrees of freedom to the number of phases and components in the system.
The phase rule is given by the equation:
F = C - P + 2
Where F is the degree of freedom, C is the number of components, and P is the number of phases.
In this case, we have:
C = 2 (water and air)
P = 2 (solid and gas)
Substituting these values into the phase rule equation:
F = 2 - 2 + 2
F = 2
Therefore, the degree of freedom for a mixture of ice and vapor is 2.
In the case of a mixture of ice and vapor, we have two phases present: solid (ice) and gas (vapor). The number of components in this system is also two: water and air. To determine the degree of freedom, we need to consider the phase rule, which relates the degrees of freedom to the number of phases and components in the system.
The phase rule is given by the equation:
F = C - P + 2
Where F is the degree of freedom, C is the number of components, and P is the number of phases.
In this case, we have:
C = 2 (water and air)
P = 2 (solid and gas)
Substituting these values into the phase rule equation:
F = 2 - 2 + 2
F = 2
Therefore, the degree of freedom for a mixture of ice and vapor is 2.
Phase rule is concerned only with the __________ properties of the system.- a)Intensive
- b)Extensive
- c)Both intensive and extensive
- d)Neither intensive nor extensive
Correct answer is option 'A'. Can you explain this answer?
Phase rule is concerned only with the __________ properties of the system.
a)
Intensive
b)
Extensive
c)
Both intensive and extensive
d)
Neither intensive nor extensive
|
|
Vivek Khatri answered |
Phase rule is concerned only with the Intensive properties of the system.
For water system, the number of phases at the triple point is _____________- a)0
- b)1
- c)2
- d)3
Correct answer is option 'D'. Can you explain this answer?
For water system, the number of phases at the triple point is _____________
a)
0
b)
1
c)
2
d)
3
|
|
Vivek Khatri answered |
Since at the triple point, the degree of freedom is zero, while applying the formula F = C - P + 2, we get the number of phases as three because C = 1, F = 0 (since water system forms only single component).
Gibbs phase rule can be applied to the systems which are in- a)Saturation
- b)Equilibrium
- c)Critical state
- d)Supercritical state
Correct answer is option 'B'. Can you explain this answer?
Gibbs phase rule can be applied to the systems which are in
a)
Saturation
b)
Equilibrium
c)
Critical state
d)
Supercritical state
|
|
Vivek Khatri answered |
Gibbs phase rule can be applied to the systems which are in equilibrium.
The number of independent properties that have to be specified to determine all the intensive properties of each phase of the system of interest is the number of degrees of freedom.
The above given statement is- a)True
- b)False
- c)Depends on a system`s properties
- d)None of the mentioned
Correct answer is option 'A'. Can you explain this answer?
The number of independent properties that have to be specified to determine all the intensive properties of each phase of the system of interest is the number of degrees of freedom.
The above given statement is
The above given statement is
a)
True
b)
False
c)
Depends on a system`s properties
d)
None of the mentioned
|
|
Vivek Khatri answered |
The number of independent properties that have to be specified to determine all the intensive properties of each phase of the system of interest is the number of degrees of freedom.
Chapter doubts & questions for Phase Equilibrium - Topicwise Question Bank for IIT JAM/CSIR/GATE Chemistry 2025 is part of Chemistry exam preparation. The chapters have been prepared according to the Chemistry exam syllabus. The Chapter doubts & questions, notes, tests & MCQs are made for Chemistry 2025 Exam. Find important definitions, questions, notes, meanings, examples, exercises, MCQs and online tests here.
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