chemistry : class12 Reversibility of Macromolecular Colloids : Macromolecular colloids : Surface Chemistry MCQ Questions and Answers
Practice important
Reversibility of Macromolecular Colloids
MCQ questions and answers.
Page 1
of
1
|
10
MCQ Questions
1. What is meant by the reversibility of a macromolecular colloid?
A.
It can be converted into a true solution permanently
B.
It can be reconverted into the colloidal state after separation of the dispersion medium
C.
It changes into a lyophobic sol on heating
D.
It always forms a precipitate on cooling
Correct Answer:
It can be reconverted into the colloidal state after separation of the dispersion medium
Explanation:
Macromolecular colloids are reversible because the dispersed substance can often be separated by removing the dispersion medium and then redispersed by adding the medium again.
2. Which type of colloid generally shows reversibility?
A.
Lyophilic colloid
B.
Lyophobic colloid
C.
Coarse suspension
D.
True solution only
Correct Answer:
Lyophilic colloid
Explanation:
Macromolecular colloids are usually lyophilic and can be redispersed in the dispersion medium after separation, making them reversible.
3. Which substance can form a reversible macromolecular colloid in water?
A.
Starch
B.
Sodium chloride crystals
C.
Sand
D.
Copper metal pieces
Correct Answer:
Starch
Explanation:
Starch is a macromolecular substance that forms a lyophilic colloid in water and can generally be redispersed after drying.
4. What usually happens when water is removed from a reversible macromolecular colloid?
A.
The macromolecule is always destroyed
B.
The macromolecule can often be obtained and redispersed later
C.
The macromolecule becomes a gas
D.
The macromolecule changes into a metal
Correct Answer:
The macromolecule can often be obtained and redispersed later
Explanation:
In a reversible macromolecular colloid, removal of the dispersion medium does not permanently destroy the macromolecule, which can often be dispersed again.
5. A dried gelatin sample forms a colloidal sol again when water is added. This property is called:
A.
Coagulation
B.
Peptisation
C.
Reversibility
D.
Sedimentation
Correct Answer:
Reversibility
Explanation:
The ability of dried gelatin to form the colloidal sol again on adding water demonstrates the reversible nature of macromolecular colloids.
6. Which property helps macromolecular colloids to be reversible?
A.
Strong attraction between the macromolecule and the dispersion medium
B.
Complete absence of interaction with the dispersion medium
C.
Very large particle size like ordinary sand
D.
Permanent chemical decomposition in the medium
Correct Answer:
Strong attraction between the macromolecule and the dispersion medium
Explanation:
Macromolecules in lyophilic colloids have a strong affinity for the dispersion medium, which allows them to become dispersed again after separation.
7. Which of the following is an example of a reversible macromolecular colloid?
A.
Gelatin in water
B.
Dust in air
C.
Sand in water
D.
Chalk in water
Correct Answer:
Gelatin in water
Explanation:
Gelatin is a macromolecular substance that forms a lyophilic and reversible colloid when dispersed in water.
8. On adding water to dried gum, the original colloidal sol is formed again. Gum is therefore a:
A.
Reversible macromolecular colloid
B.
Permanent suspension
C.
Non-dispersible solid
D.
Lyophobic metal sol
Correct Answer:
Reversible macromolecular colloid
Explanation:
Gum can be redispersed in water after drying, which is characteristic of reversible macromolecular colloids.
9. Why are macromolecular colloids called reversible colloids?
A.
They can repeatedly change colour
B.
Their colloidal state can be restored after removal and readdition of the dispersion medium
C.
They always undergo irreversible coagulation
D.
They contain only inorganic particles
Correct Answer:
Their colloidal state can be restored after removal and readdition of the dispersion medium
Explanation:
Reversibility refers to the restoration of the colloidal dispersion when the dispersion medium is added again to the separated macromolecular substance.
10. Which statement about a reversible macromolecular colloid is correct?
A.
It cannot be dispersed again after drying
B.
It can usually be redispersed in the same dispersion medium
C.
It is always formed from metal particles
D.
It must immediately settle under gravity
Correct Answer:
It can usually be redispersed in the same dispersion medium
Explanation:
The defining feature of a reversible macromolecular colloid is its ability to regain the colloidal state when the appropriate dispersion medium is added again.
Short Questions and Answers
Practice short questions and answers related to
Reversibility of Macromolecular Colloids
.
Short questions are currently unavailable for this page.