Dispersion System

Question 1

Dispersed Phase

Answer 1

Internal/Discontinuous Phase

Question 2

Dispersion Medium

Answer 2

External/Continuous Phase

Question 3

Classificiation of Dispersed Systems based on Particle Size

Answer 3

Molecular Dispersion
Colloidal Dispersion
Coarse Dispersion

Question 4

Mixture of two or more components that form a homogenous molecular dispersion or one-phase system

Answer 4

Molecular Dispersion (True Solutions)

Question 5

Represents a system having a particle size intermediate between that of a true solution & a coarse dispersion

Answer 5

Colloidal Dispersion

Question 6

Diameter of particles being larger than 0.5 um

Answer 6

Coarse Dispersion

Question 7

Molecular Dispersion

Answer 7

Size: <1nm
State: Monophasic
Visibility: Invisible in electron microscope
Filtration: Pass through ultrafilter and semipermeable membrane
Diffusion: Rapid

Question 8

Examples of Molecular Dispersion

Answer 8

Glucose
Oxygen Molecules
Ordinary Ions

Question 9

Colloidal Dispersion

Answer 9

Size: 1nm - 0.5um
State: Biphasic
Visibility: Visible in electron Microscope
Filtration: Pass through filter paper but not semipermeable membrane
Diffusion: Slow

Question 10

Examples of Colloidal Dispersion

Answer 10

Colloidal Silver Solution
Paint
Shaving Cream
Natural & Synthetic Polymers
Milk, Cheese, Butter

Question 11

Coarse Dispersion

Answer 11

Size: >0.5um
State: Biphasic
Visibility: Visible under microscope
Filtration: Do not pass through filter paper or semipermeable membrane
Diffusion: No diffusion

Question 12

Examples of Coarse Dispersion

Answer 12

Most pharmaceutical emulsion and Suspension
Grains of Sand
Red Blood Cells

Question 13

Types of Colloidal System

Answer 13

(a) Lyophilic Colloids
(b) Lyophobic Colloids
(c) Association Colloids

Question 14

Lyophilic Colloids

Answer 14

Solvent loving colloids
Thermodynamically Stable
Dispersion Medium: Water

Question 15

Examples of Lyophilic Colloids

Answer 15

Dispersion of starch, gum, protein in water

Question 16

Lyophobic Colloids

Answer 16

Solvent-hating Colloids
Thermodynamically Stable
Dispersion Medium: Water - Hydrophobic colloids
Consist of inorganic particles

Question 17

Examples of Lyophobic Colloids

Answer 17

Dispersion of Gold, Sulfur, Silver iodide in water

Question 18

Composed of material that have little attraction for the dispersion medium, due primarily to the absence of a solvent sheath around the particles

Answer 18

Lyophobic Colloids

Question 19

Association Colloids / Amphiphilic Colloids

Answer 19

Having two distinct regions of opposing solution affinities

Question 20

Formed by association of dissolved molecules of a substance to create particles of colloidal dimensions

Answer 20

Association / Amphiphilic Colloids

Question 21

Systems containing colloidal particles that interact to an appreciable extent with the dispersion medium

Answer 21

Lyophilic Colloids

Question 22

The concentration of monomer at which micelles form

Answer 22

Critical Micelle Concentration

Question 23

The number of monomers that aggregate to form a micelle

Answer 23

Aggregation Number

Question 24

Dispersion Medium: Solid

Answer 24

Solid: Solid Solution
Liquid: Solid Emulsion
Gas: Solid Foam

Question 25

Dispersion Medium: Liquid

Answer 25

Solid: Sol, Gel Liquid: Emulsion Gas: Foam

Question 26

Dispersion Medium: Gas

Answer 26

Solid: Solid aerosols Liquid: Liquid Aerosols

Question 27

Colloid Type of Pearls, Opal

Answer 27

Solid solution

Question 28

Colloid Type of Cheese, butter

Answer 28

Solid emulsion

Question 29

Colloid Type of Pumcie, Marshmallow

Answer 29

Solid Foam

Question 30

Colloid Type of Jelly, Paint

Answer 30

Sol, Gel

Question 31

Colloid Type of Milk, Mayo

Answer 31

Emulsion

Question 32

Colloid Type of Whipped cream, shaving cream

Answer 32

Foam

Question 33

Colloid Type of Smoke, Dust

Answer 33

Solid aerosols

Question 34

Colloid Type of Cloud, mist, fog

Answer 34

Liquid aerosols

Question 35

Properties of Colloids

Answer 35

**1. Optical** * Light Scattering **2. Kinetic** * Brownian Motion * Diffusion * Sedimentation * Viscosity **3. Electrical** * Zeta Potential * Nerns't Potential * Electrokinetic Potential

Question 36

Optical properties

Answer 36

Faraday-Tyndall Effect

Question 37

Random movement of colloidal particles, irregular & zigzag pattern

Answer 37

Brownian Motion

Question 38

Factors affecting Brownian Motion

Answer 38

↑ Particle Size ↓ Velocity ↑ Viscosity ↓ Brownian Movement Size of particles MW Affinity of particle Spherocolloids - ↓ Viscosity Linear particles - ↑ Viscosity

Question 39

**Spontaneous movement** of particles from a region of **higher concentration** to one of **lower concentration** until equilibrium is achieved.

Answer 39

Diffusion *Ruled by Fick's law*

Question 40

Resistance to flow a system under applied stress

Answer 40

Viscosity

Question 41

Zeta Potential is also known as

Answer 41

Electrokinetic Potential

Question 42

**Difference in potential** between the surface of the **tightly-bound layers** & the **electroneutral region** of the dispersion

Answer 42

Zeta Potential/Electrokinetic Potential

Question 43

Nerns't Potential

Answer 43

Electrokinetic Potential

Question 44

**Difference in potential** between the **actual surface** of the particle & the **electroneutral region** of the dispersion

Answer 44

Nerns't Potential/Electrothermodynamic Potential

Question 45

Electrokinetic phenomena

Answer 45

Electrophoresis Electro-osmosis Sedimentation Potential Streaming Potential

Question 46

The presence and magnitude, or absence of this on colloidal particle is an important factor in determining **stability of colloids**

Answer 46

Electric Properties

Question 47

The **movement** of a **charged particles** through a **liquid** under the influence of an **applied potential difference**

Answer 47

Electrophoresis/Cataphoresis

Question 48

The **movement** of the **dispersion medium** under the influence of **applied potential**

Answer 48

Electro-osmosis

Question 49

**Creation of potential** when particles undergo **sedimentation** **Opposite of electrophoresis**

Answer 49

Sedimentation Potential

Question 50

**Creation of potential** by a **forcing a liquid** to **flow** through a **plug** or **bed** of particles

Answer 50

Streaming potential

Question 51

Pharmaceutical use of **Colloidal Copper**

Answer 51

Treatment of Cancer

Question 52

Pharmaceutical use of **Colloidal Mercury**

Answer 52

Treatment of Syphilis

Question 53

Pharmaceutical use of **Colloidal Gold**

Answer 53

Diagnostic Agent for paresis

Question 54

Pharmaceutical use of **Colloidal Electrolytes**

Answer 54

Inc. solubility, stability, and taste of compounds in aq and oil pharmaceutical prep

Question 55

Pharmaceutical use of **Colloidal Sulfur**

Answer 55

Absorbed completely compare to powdered sulfur