1. Heterogeneous Mixtures

2. 1. Suspensions
Suspension – a mixture containing particles that settle out if left undisturbed.
Particles are too large to be dissolved.
Particles are greater than 1000 nm in diameter.
They can be filtered.
Examples : muddy water, many “liquid” medicines that require “shaking,”

4. 2. Colloids
Colloid – Heterogeneous mixture of intermediate size particles. They do not dissolve or settle.
These particles remain dispersed in the solution, they “float” and are suspended.
Particles cannot be removed by filtering.
They are between 1 nm and 1000 nm in diameter.
The most abundant substance in a colloid is the dispersion medium.

5. If you stir an electrolyte into the colloid, it will cause the particles to settle out.
“Flocculents” bring the colloid particles together and the mass becomes so great that it forms a suspension.
Examples of colloids include smog, fog, milk, mayonnaise, marshmallow, smoke, clouds.

6. Colloids are classified as : sol, gels, emulsions, foam, and aerosols.
Sol – a solid dispersed in a liquid
Examples : paints, blood
Gel – a solid network extending throughout a liquid.
Example : gelatin (jello)
Liquid emulsion – liquid dispersed in a liquid
Examples : milk, mayonnaise
Solid emulsion – liquid dispersed in a solid
Examples : cheese, butter

8. Foam – gas dispersed in liquid
Examples : shaving cream, whipped cream, beaten egg white
Solid Foam – Gas dispersed in a solid
Examples : marshmallow, soaps that float
Solid aerosol – solid dispersed in gas (air)
Examples : smoke, air borne particulate matter, auto exhaust
Liquid aerosol – liquid dispersed in gas (air)
Examples : fog, mist, clouds, aerosol spray

9. Brownian motion – the random, erratic motion of colloid particles.
Caused by the polar areas of the molecules. They attract and repel each other, keeping them in constant motion.
Tyndall Effect – particles in a colloid are large enough to scatter light.
Turbidity – how cloudy the water is.

11. Colloid
Type
Dispersed substance
Dispersing Medium
Examples
Solid Sol
Solid
Colored gems
Sol
Liquid
Blood
Gel
Solid Network
Gelatin
Solid Emulsion
Butter, Cheese
Liquid Emulsion
Milk, mayonnaise
Solid Foam
Gas
Marshmallow, soaps that float
Foam
Shaving cream, whipped cream
Solid Aerosol
Smoke, dust in air
Aerosol
Fog, aerosol spray, clouds

12. Colloid
Type
Dispersed substance
Dispersing Medium
Examples