Similar Materials

We need to distinguish between solutions and other similar materials such as pure liquids, colloidal dispersions and suspensions.

Components of Solutions

Every solution has at least two components. The components of a solution are the solute and the solvent. The solvent is the primary component. The solute is the material that is dissolved in the solvent. For example, in salt water, salt is the solute and water is the solvent. Often there is more than one solute in a solution and sometimes more than one solvent.

Pure Liquid

At the observable level, the distinction between solutions and pure liquids is this. The components of a solution can be separated from one another by simple phase change operations like evaporation or distillation. On the other hand, a pure liquid will go through those same kinds of changes, without being separated into components.

Suspensions and Colloidal Dispersions

There are two other kinds of mixtures that are somewhat similar to solutions that you need to know about. They are called suspensions and colloidal dispersions. Here are some examples of dispersions and suspensions. Look at these samples and write down physical descriptions of them in exercise 2 in your workbook.


suspension	colloidal dispersion	solution

In a suspension, the particles which are temporarily suspended in the liquid are large enough to collectively make the material appear cloudy. They will settle out after a while. You can now see that after several minutes, the particles in the suspension have settled to the bottom.
In a colloidal dispersion, we have very small particles spread throughout the liquid which are large enough to reflect light, but not large enough to be seen individually. A colloidal dispersion may look either clear or cloudy in ordinary room light. The particles in a colloidal dispersion remain dispersed in the liquid and will not settle out.
A solution, on the other hand, will appear clear even when a light is shown through it.

Top of Page

E-mail instructor: Eden Francis
Physical Science
19600 South Molalla Avenue
Oregon City, OR 97045
(503) 657-6958 x2807
FAX (503)-650-6657

TDD (503) 650-6649

Distance Learning questions

Clackamas Community College
Š1998, 2003 Clackamas Community College, Hal Bender