Introduction to Mixtures and Distillation

A mixture is a physical blend of two or more components that can be separated.
Heterogeneous mixtures are non-uniform; you can see different components, such as rocks and sand or soil.
Homogeneous mixtures are uniform in appearance, meaning the components cannot be visually distinguished.
If a homogeneous mixture is a solid, it is simply called homogeneous; if it is a liquid, it is defined as a solution.

Solute: This is the substance that gets dissolved. Examples include antacid tablets or Kool-Aid mixture.
Solvent: This is the component present in the greatest amount. While usually water, other substances can be used.

Temperature: Substances dissolve more quickly as the temperature increases.
Particle Size: Smaller particles dissolve or melt faster than larger ones (e.g., chopped butter in macaroni and cheese).
Mixing: Agitation, such as stirring a copper chloride mixture, speeds up the dissolution process.
Nature of the Solute and Solvent: Some chemicals naturally dissolve faster than others or work more efficiently with specific solvents.

Manual Separation: Components can be separated by hand, although this is often a long and tedious process for materials like sand.
Filtration: This method separates solid materials from liquids. It involves folding a circular piece of filter paper into quarters—with three flaps on one side and one on the other—and placing it in a funnel.
Distillation: A process used to separate liquids based on differing boiling points.

The distillation apparatus consists of five basic parts:
- Thermometer (used to measure boiling points)
- Distillation flask (where the mixture is boiled)
- Bunsen burner (the heat source)
- Condensing tube (includes an inner tube for gas and an outer tube for cooling water)
- Receiving flask (where the final liquid is collected)
During distillation, the solution in the flask boils and turns into a gas. This gas enters the condensing tube, where it cools and turns back into a liquid before falling into the receiving flask.
In a mixture of water and ethyl alcohol, the alcohol is recovered first because it has a lower boiling point.

Why is the soil from Atlanta or parts of the Missouri River red?
- The red color is caused by the presence of iron in the soil, which has rusted.
Why should a homemade "lava lamp" (oil, water, and antacid tablets) not be sealed?
- The dissolving tablets produce gas that builds up pressure; if the container is closed, it could explode.
How can two clear, colorless liquids like water and ethyl alcohol be differentiated without tasting them?
- They can be identified by scent or by a flammability test; ethyl alcohol will light on fire while water will not.
When is the unit test that includes the distillation essay question?
- The test is scheduled for September 1 and is worth 10 points.