1. Separation Techniques
Solutions

2. Why would we want to separate mixtures?
to purify water so that it is safe to drink
to extract a mineral from rocks to be able to use (example, quartz or gold)
to eliminate the pulp in freshly squeezed juice
to make soup broth

3. What we have to think of when we separate mixtures…
We need to look for a difference between the parts of the mixture and then use a separation method that takes advantage of this difference.
These are some of the properties that can be used:
The size of the particles
The density of a substance
The boiling point of a substance
The solubility of a substance

4. Ways to Separate Mixtures
There are several ways of separating mixtures. The ones we will be focusing on are:
Sedimentation & Decantation
Filtration
Distillation
Magnetism

5. Sedimentation and decantation
AKA : settling out and pouring out
When it works:
The size of the particles of a substance have to be large enough to settle to the bottom of the container.
The larger the size of the particles the faster they will settle to the bottom of the container.
The liquid above the sedimented particles should be quite clear and can be poured off easily.
This method only works for heterogeneous mixtures!
When it doesn’t work:
As the size of the particles get smaller , it may take too long for them to settle to the bottom of the container and the particles may also be easily stirred up if we try to pour off the liquid above the particles .

6. Sedimentation
Decantation

7. Examples:
noodles or vegetables in a soup settle to the bottom
muddy water (mud settles to the bottom)
orange juice that has pulp
salad dressing made of oil and vinegar

8. Filtration Downfall: When it works: Vocabulary:
The size of the particles of a substance have to be too large to pass through the holes of a filter .
This method only works for heterogeneous mixtures!
Downfall:
Filtration takes time and may take longer as the residue accumulates on the filter.
Vocabulary:
Residue: is what is left on the filter
Filtrate: is the liquid that passes though the filter

9. Mixture of
solid and
liquid
Stirring
rod
Filtrate (liquid
component
of the mixture)
Filter paper
traps solid
Funnel

10. Distillation When it works: When it Doesn’t work Vocabulary
The substance in the mixture with the lowest boiling point will evaporate first and will then condense in another cooled container.
This method is the only one that works for SOLUTIONS! (homogeneous mixture)
When it Doesn’t work
-This method cannot be used if 2 substances have the same boiling point
Vocabulary
Distillate: is the liquid that evaporates
Residue: is the substance left behind in the original container

11. .
Separates homogeneous mixture on the basis of differences in boiling point

12. Examples: separating salt from saltwater
making distilled water in the lab
commercially distilling alcohol (ethanol used for thermometers)

13. MAGNETISM When it works:
-Can separate metal particles when they are magnetic (contain nickel, cobalt, iron, etc)