1. Separating Mixtures

2. How can you Separate Mixtures?
A mechanical mixture has a heterogeneous composition.
Since the types of particles in the mixture are not strongly attracted to each other, they can be separated by a number of different ways.

3. Ways to Separate Mixtures
Heterogeneous mixtures can be separated in the following ways:
Settling or Floating
Filtration
Magnetism
By hand
Dissolving and evaporating

4. Settling or Floating
Settling or Floating: When mixtures are separated into layers because of their density (meaning some float and some sink), we can separate them by skimming, pumping, or pouring off the layers.

5. Filtration
Filtration: Different sized of filters are available, ranging from filters capable of capturing bacteria, to those used to sieve gravel.

6. Magnetism
Magnetism: Magnets can be used to separate particles such as iron, nickel or cobalt from non-magnetic materials.

7. By Hand
By Hand: Large particles that are easily identifiable can be separated by hand. For example, it would be easy to separate pieces of Trail Mix.

8. Dissolving and Evaporating
Dissolving and Evaporating: Certain solvents can be used to dissolve a solute and separate it from a mixture. The solute can then be recovered by evaporating the solvent.

9. Separating Mixtures Questions
1. Explain which separating techniques you might use to separate the substances in each of the mixtures:
Water, sugar and sand
Water flour and marbles
Vegetable soup, salt and water
Water iron fillings and soil

10. Questions Continued…
2. Draw a flow chart to show hoe you would separate a mixture of iron fillings, sand, salt, stones, and sawdust.
3. Explain why settling isn’t always used to separate particles suspended in a liquid?