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GRADE 7 SCIENCE
Separating Solutions
STUDENT ACTIVITY:
Discuss with a partner
how you would separate
the following mixtures…
 Salt water
 Muddy water
 Nuts and bolts
Iron
filings and sand
Vegetable oil and sand
Vegetable oil and water
Salt and pepper
Be prepared to defend
your answers!
DISCUSSION QUESTION
“Are the components you
have separated still
mixtures, or are they
pure? Why or why not?”
SEPARATION TECHNIQUES
Mechanical Sorting:
Used to separate the
parts of a mixture based
on properties such as
particle size.
Examples: floatation &
magnetism
magnetism
floatation
FILTRATION:
A
common way to
separate solid particles
from a mixture
The filters can have
holes of varying sizes…
small to microscopic.
Coffee filter
Oil filter
Colander
Furnace filter
EVAPORATION:
of state from a
liquid to a gas.
Used to recover a solid
solute from a solution.
Change
DISTILLATION:
Uses
two changes of
state: evaporation and
condensation.
It allows you to recover
BOTH the solute and
solvent from a solution.
Condensation
Evaporation
PAPER CHROMATOGRAPHY:
Used
to separate the
colored substances in a
mixture such as ink.
Used to separate the
solvents in a mixture.
SEPARATION TECHNIQUES
IN THE HOME:
Colanders
Clothes
dryers
Window screens
Coffee percolators
Salad spinners
Any others?