Notes: Mixtures

CW: Substances vs Mixtures

H: More about Mixtures

Mixtures

November 12, 2008

ObjectivesObjectives

1. Describe the properties of mixtures

2. Compare a mixture to a substance

3. Name common separation techniques for a mixture

4. Define mixture, homogeneous, heterogeneous, distillation, filtration, chromatography

MixtureMixture

• Two or more kinds of elements or compounds combined without a chemical reaction.

• Individual components maintain their individual properties.

Physical properties may change.

Their atoms do not change.

Mixtures do not combine in definite amounts. They can be present in any ratio.

Mixture Classification Mixture Classification

Mixtures are classified according to how well they are mixed.

• Heterogeneous

• Homogeneous

Separation Techniques

Manually

Settling

Centrifuge is a device in which solid or liquid particles of different densities are separated by rotating them in a tube in a horizontal circle.

Filtration• Separates a solid from

a liquid through the use of a porous material as a filter.

• Paper, charcoal, or sand can serve as a filter.

Magnetism

Chromatography

Separates mixtures into the chemicals from which they are made.

Distillation

Solution is heated until it boils. The liquid with the lowest boiling point boils first and becomes a gas.

Decantation

• Separates a liquid from insoluble solid sediment by carefully pouring the liquid from the solid without disturbing the solid