Emulsions 2

In an emulsion the velocity of sedimentation is found to be negative. It means that the creaming is

• Absent

• In both the directions

• In downward direction

• In upward direction

For a stable emulsion,the phase volume ratio is generally in oil

• 26/74

• 52/48

• 74/26

• 74/100

In an emulsion which instability step is prevented by emulsifiers

• Breaking

• Coalescence

• Creaming

• Flocculation

The distribution of globules is not uniform in an emulsion. This stage is termed as

• Breaking

• Caking

• Coalescence

• Creaming

The HLB range of an emulsifier employed in the preparation of water in oil emulsion is

• 3-6

• 7-12

• 13-15

• More than 15

On commercial scale emulsions are prepared by

• Centrifugation

• Dialysis

• Freezing

• Homogenization

Microemulsion is not considered to be a true emulsion, because

• Appearance of transparent

• Emulsifier is not used

• Immiscible phase is absent

• Internal phase is not spherical

An O/W microemulsion is prepared using a hydrophilic surfactant. The appearance of the microemulsion is:

• Intense white

• Milky White

• Translucent

• Transparent

Preservatives are added to

• Control microbial growth

• Increase shelf Life

• Both

• None

Which rule describes the relationship between the nature of emulsifying agent and type of emulsion formed

• Stoke's law

• Bancroft's rule

• Both

• None