Practice important
Coagulation Resistance
MCQ questions and answers.
Page 1
of
1
|
10
MCQ Questions
1. Macromolecular colloids generally resist coagulation mainly because their particles are surrounded by a layer of
A.
Solvent molecules
B.
Gas molecules
C.
Metal ions only
D.
Precipitated salt
Correct Answer:
Solvent molecules
Explanation:
Macromolecular colloids are strongly solvated or hydrated. The layer of solvent molecules around the particles helps prevent their aggregation and coagulation.
2. Which type of colloid generally has greater resistance to coagulation?
A.
Lyophilic colloid
B.
Lyophobic colloid
C.
Suspension
D.
True solution
Correct Answer:
Lyophilic colloid
Explanation:
Lyophilic colloids, including many macromolecular colloids, have strong attraction between the dispersed particles and the dispersion medium, giving them greater coagulation resistance.
3. The stability of a macromolecular colloid is increased by strong
A.
Solvation of its particles
B.
Sedimentation of its particles
C.
Evaporation of the medium
D.
Crystallisation of its particles
Correct Answer:
Solvation of its particles
Explanation:
Solvation forms a protective layer around macromolecular colloidal particles, making it difficult for them to come together and coagulate.
4. A substance added to a lyophobic sol to protect it from coagulation is called a
A.
Protective colloid
B.
Coagulating electrolyte
C.
Dispersing precipitate
D.
Dehydrating agent
Correct Answer:
Protective colloid
Explanation:
A protective colloid, usually a lyophilic or macromolecular colloid, surrounds the particles of a lyophobic sol and increases their resistance to coagulation.
5. Which of the following can act as a protective colloid because it is a macromolecular colloid?
A.
Gelatin
B.
Sodium chloride
C.
Hydrochloric acid
D.
Potassium nitrate
Correct Answer:
Gelatin
Explanation:
Gelatin is a macromolecular lyophilic colloid. It can form a protective layer around dispersed particles and prevent their coagulation.
6. The protective action of a macromolecular colloid occurs mainly because it
A.
Forms a coating around the sol particles
B.
Converts the sol into a true solution
C.
Removes all solvent molecules
D.
Changes the particles into crystals
Correct Answer:
Forms a coating around the sol particles
Explanation:
Macromolecules get adsorbed on the surface of sol particles and form a protective coating, which prevents particle-to-particle contact and coagulation.
7. The gold number of a protective colloid is a measure of its
A.
Protective power
B.
Electrical conductivity
C.
Density
D.
Boiling point
Correct Answer:
Protective power
Explanation:
Gold number indicates the amount of protective colloid needed to prevent coagulation of a standard gold sol. It is used to compare protective action.
8. A protective colloid with a lower gold number has
A.
Greater protective power
B.
Lower protective power
C.
No coagulation resistance
D.
Greater electrical charge only
Correct Answer:
Greater protective power
Explanation:
A lower gold number means that a smaller amount of the protective colloid is needed to prevent coagulation, so its protective power is greater.
9. Which substance is commonly used as a protective colloid for gold sol?
A.
Gelatin
B.
Sodium chloride
C.
Potassium sulfate
D.
Calcium chloride
Correct Answer:
Gelatin
Explanation:
Gelatin is a lyophilic macromolecular colloid and protects gold sol particles from coagulation by forming a protective layer around them.
10. Coagulation resistance of macromolecular colloids is generally associated with their
A.
High affinity for the dispersion medium
B.
Complete insolubility in the medium
C.
Rapid settling under gravity
D.
Formation of large crystals
Correct Answer:
High affinity for the dispersion medium
Explanation:
Macromolecular colloids have a strong affinity for the dispersion medium. This causes solvation or hydration of their particles and increases resistance to coagulation.
Short Questions and Answers
Practice short questions and answers related to
Coagulation Resistance
.
Short questions are currently unavailable for this page.