Q. In the context of surface chemistry, what does the term 'adsorption' refer to? (2022)
A.
The process of a substance being taken up by a liquid
B.
The process of a substance adhering to a surface
C.
The process of a substance dissolving in a solvent
D.
The process of a substance being absorbed into a solid
Show solution
Solution
Adsorption refers to the process where molecules adhere to the surface of a solid or liquid, forming a film.
Correct Answer: B — The process of a substance adhering to a surface
Learn More →
Q. In the context of surface chemistry, what does the term 'desorption' mean? (2023)
A.
The process of adsorption
B.
The release of adsorbed molecules from a surface
C.
The absorption of a gas into a liquid
D.
The formation of a solid from a gas
Show solution
Solution
Desorption refers to the process where adsorbed molecules are released from the surface back into the gas or liquid phase.
Correct Answer: B — The release of adsorbed molecules from a surface
Learn More →
Q. In the context of surface chemistry, what does the term 'desorption' refer to? (2022)
A.
The process of adsorption
B.
The release of adsorbate from the surface
C.
The formation of a new layer
D.
The increase in surface area
Show solution
Solution
Desorption refers to the process by which an adsorbate is released from the surface of the adsorbent.
Correct Answer: B — The release of adsorbate from the surface
Learn More →
Q. In the context of surface chemistry, what does the term 'surface area' refer to? (2020)
A.
Total area of the solid
B.
Area available for adsorption
C.
Area of the bulk material
D.
Area of the gas
Show solution
Solution
In surface chemistry, 'surface area' refers to the area available for adsorption, which is crucial for determining the adsorption capacity.
Correct Answer: B — Area available for adsorption
Learn More →
Q. In the Langmuir adsorption isotherm, which assumption is NOT made? (2019)
A.
Adsorption occurs on a surface with a finite number of identical sites
B.
Adsorption is reversible
C.
There is no interaction between adsorbed molecules
D.
Adsorption occurs only at high pressures
Show solution
Solution
The Langmuir isotherm assumes that adsorption occurs at all pressures, not just high pressures.
Correct Answer: D — Adsorption occurs only at high pressures
Learn More →
Q. The Freundlich adsorption isotherm is best described by which equation? (2023)
A.
x/m = kP
B.
x/m = kP^(1/n)
C.
P = k(x/m)
D.
P = k(x/m)^(1/n)
Show solution
Solution
The Freundlich isotherm is represented by the equation x/m = kP^(1/n), where x is the amount adsorbed, m is the mass of the adsorbent, and P is the pressure.
Correct Answer: B — x/m = kP^(1/n)
Learn More →
Q. The term 'adsorption' refers to: (2022)
A.
The process of a substance being taken up by a liquid.
B.
The accumulation of molecules on a surface.
C.
The mixing of two liquids.
D.
The dissolution of a solid in a liquid.
Show solution
Solution
Adsorption is the process where molecules accumulate on the surface of a solid or liquid.
Correct Answer: B — The accumulation of molecules on a surface.
Learn More →
Q. What is the primary difference between physisorption and chemisorption? (2023)
A.
Physisorption is stronger than chemisorption
B.
Chemisorption involves chemical bonds, while physisorption involves van der Waals forces
C.
Physisorption is irreversible, while chemisorption is reversible
D.
Chemisorption occurs at lower temperatures than physisorption
Show solution
Solution
The primary difference is that chemisorption involves the formation of chemical bonds, while physisorption involves weaker van der Waals forces.
Correct Answer: B — Chemisorption involves chemical bonds, while physisorption involves van der Waals forces
Learn More →
Q. What is the significance of the Langmuir isotherm in surface chemistry? (2023)
A.
It describes multilayer adsorption.
B.
It assumes a fixed number of adsorption sites.
C.
It is applicable only to physisorption.
D.
It does not consider temperature effects.
Show solution
Solution
The Langmuir isotherm assumes a fixed number of adsorption sites and describes monolayer adsorption on a surface.
Correct Answer: B — It assumes a fixed number of adsorption sites.
Learn More →
Q. What is the term for the maximum amount of adsorbate that can be adsorbed on a given mass of adsorbent? (2020)
A.
Adsorption capacity
B.
Saturation point
C.
Equilibrium concentration
D.
Adsorption isotherm
Show solution
Solution
The maximum amount of adsorbate that can be adsorbed on a given mass of adsorbent is referred to as the adsorption capacity.
Correct Answer: A — Adsorption capacity
Learn More →
Q. What is the term for the maximum amount of adsorbate that can be adsorbed on a unit mass of adsorbent? (2020)
A.
Adsorption capacity
B.
Adsorption isotherm
C.
Saturation point
D.
Adsorption efficiency
Show solution
Solution
The maximum amount of adsorbate that can be adsorbed on a unit mass of adsorbent is referred to as the adsorption capacity.
Correct Answer: A — Adsorption capacity
Learn More →
Q. What is the term for the maximum amount of solute that can be adsorbed on a given mass of adsorbent? (2023)
A.
Adsorption capacity
B.
Saturation point
C.
Equilibrium concentration
D.
Adsorption isotherm
Show solution
Solution
The maximum amount of solute that can be adsorbed on a given mass of adsorbent is referred to as the adsorption capacity.
Correct Answer: A — Adsorption capacity
Learn More →
Q. What is the term used for the process of removing adsorbed molecules from a surface? (2020)
A.
Desorption
B.
Absorption
C.
Sorption
D.
Adsorption
Show solution
Solution
Desorption is the process of removing adsorbed molecules from a surface, while adsorption is the process of molecules adhering to a surface.
Correct Answer: A — Desorption
Learn More →
Q. What type of adsorption is characterized by a low heat of adsorption, typically less than 40 kJ/mol? (2023)
A.
Physisorption
B.
Chemisorption
C.
Multilayer adsorption
D.
Surface reaction
Show solution
Solution
Physisorption is characterized by a low heat of adsorption, typically less than 40 kJ/mol, due to weak van der Waals forces.
Correct Answer: A — Physisorption
Learn More →
Q. Which of the following is a characteristic of multilayer adsorption? (2019)
A.
Occurs at low pressures only
B.
Described by the Langmuir isotherm
C.
Described by the BET theory
D.
Involves only physical adsorption
Show solution
Solution
Multilayer adsorption is described by the BET theory, which accounts for the formation of multiple layers of adsorbate on the adsorbent.
Correct Answer: C — Described by the BET theory
Learn More →
Q. Which of the following is a common method to measure surface area of adsorbents? (2019)
A.
TGA
B.
BET method
C.
DSC
D.
XRD
Show solution
Solution
The BET method (Brunauer-Emmett-Teller) is commonly used to measure the surface area of adsorbents.
Correct Answer: B — BET method
Learn More →
Q. Which of the following is NOT a method for measuring surface area of adsorbents? (2022)
A.
BET method
B.
Langmuir method
C.
TGA method
D.
Gas adsorption method
Show solution
Solution
Thermogravimetric analysis (TGA) is not a method for measuring surface area; it is used to study thermal stability and composition.
Correct Answer: C — TGA method
Learn More →
Q. Which of the following is NOT a method to increase the adsorption capacity of a solid? (2023)
A.
Increasing the surface area
B.
Increasing the temperature
C.
Using a more porous material
D.
Increasing the pressure
Show solution
Solution
Increasing the temperature generally decreases the adsorption capacity for physisorption, as it can overcome the weak van der Waals forces.
Correct Answer: B — Increasing the temperature
Learn More →
Q. Which of the following is true about the adsorption of gases on solids? (2023)
A.
It is always an exothermic process
B.
It is always an endothermic process
C.
It can be either exothermic or endothermic
D.
It does not involve energy changes
Show solution
Solution
The adsorption of gases on solids is typically an exothermic process, as energy is released when the gas molecules adhere to the surface.
Correct Answer: A — It is always an exothermic process
Learn More →
Q. Which of the following statements about chemisorption is true? (2022)
A.
It is a reversible process
B.
It involves the formation of strong chemical bonds
C.
It occurs at low temperatures
D.
It is independent of the nature of the adsorbate
Show solution
Solution
Chemisorption involves the formation of strong chemical bonds between the adsorbate and the surface, making it generally irreversible.
Correct Answer: B — It involves the formation of strong chemical bonds
Learn More →
Showing 1 to 20 of 20 (1 Pages)
