Top 80+ Solved Coarse Dispersion- Emulsion MCQ Questions Answer
Q. In an emulsion, the velocity of sedimentation is found to be negative. It means that the creaming is:
a. absent
b. in both the directions
c. in downward direction
d. in upward direction
Q. The density of the dispersed phase is more than that of the dispersion medium. According to theStokes' equation, the creaming is:
a. at the center of the emulsion
b. in both the directions
c. in downward direction
d. in upward direction
Q. When oil and water are triturated together, the interfacial free energy was observed to be increased.What does it indicate?:
a. decrease in the interfacial tension
b. decrease in the stability
c. increase in stability
d. stable film formation
Q. For a stable emulsion, the phase volume ratio is generally about:
a. 26/74
b. 52/48
c. 74/26
d. 74/100
Q. The HLB range of an emulsifier employed in the preparation of water-in-oil emulsion is:
a. 3 to 6
b. 7 to 12
c. 13 to 15
d. more than 15
Q. In case of emulsions, the viscosity immediately after preparation and during storage, respectively, willbe:
a. higher and will gradually decrease
b. higher and gradually increase
c. lower and gradually decrease
d. lower and gradually increase
Q. The distribution of globules is not uniform in an emulsion. This stage is termed as:
a. breaking
b. caking
c. coalescence
d. creaming
Q. An o/w microemulsion is prepared using a hydrophilic surfactant. The appearance of themicroemulsion is:
a. intense white
b. milky white
c. translucent
d. tr
Q. Emulsions are defined as thermodynamically unstable systems. The events that follow sequentiallytowards instability are:
a. coalescence, breaking, creaming and flocculation
b. coalescence, flocculation, creaming and breaking
c. flocculation, creaming, breaking and coalescence
d. flocculation, creaming, coalescence and breaking
Q. In the stability of emulsion, which instability step is prevented by emulsifiers?:
a. breaking
b. coalescence
c. creaming
d. flocculation
Q. The main function of an emulsifier in the preparation of an emulsion is to:
a. develop a condensed membrane layer film
b. increase the repulsions between globules coming together
c. increase the surface free energy
d. reduce the interfacial tension
Q. An emulsifier can be regarded as superior, if its mechanism of action is based on the principle of:
a. developing solid adsorption film
b. forming monomolecular adsorption film
c. generating multimolecular adsorption film
d. increasing interfacial energy
Q. An emulsifier is considered to be ideal, if it is soluble in:
a. aqueous, oil and gas phases
b. aqueous phase only
c. both aqueous and oil phase
d. oil phase only
Q. On commercial scale, emulsions are prepared by::
a. centrifugation
b. dialysis
c. freezing
d. homogenization