Name: __________________________________
Lab #: _____
DUE DATE: _____________________________
Period: _____
LAB: “Separating Several Substances”
Introduction:
When two elements combine, a chemical reaction does not always happen
between them. Instead, the two elements form a mixture in which the properties of the
two elements still exist. Mixtures are any two substances that are combined physically.
The two elements, or any substance in a mixture, can be separated based on
differences in their physical properties. For example, if you have a jar full of colored
beads, you can separate them by color or size. In this investigation you will observe
how physical properties are affected when two elements are combined.
Purpose:
To separate substances using physical properties.
To observe homogeneous and heterogeneous mixtures.
Materials:
Sand
Salt
Iron files
2 beakers
Magnet
Scoopula
Hand lens
Water
Funnel
Watch Glass
Filter Paper
Petri Dishes
Stirring Rod
Safety Goggles
Hot Plate (setting 8)
Procedure A: Understanding a Mixture – “Seeing Several Substances”
1.
2.
3.
On one half of a piece of filter paper, put 1-scoop of salt.
On the other half of the same filter paper, put 1-scoop of sand.
Using a hand lens, observe and each substance carefully.
 Is salt (NaCl) a pure substance (same throughout)?
YES
NO
 Is sand a pure substance (same throughout)?
YES
NO
Describe what the grains for both sand and salt look like:
SAND: ____________________________________________________________
SALT: ____________________________________________________________
4.
Draw a sampling of the grains (3) you observed for each of the following:
SALT:
SAND:
Procedure B: Forming a Mixture – “Combining Several Substances:”
1.
2.
3.
Pour both the salt & sand from your filter paper into one empty beaker.
Add 50 ml of water to the beaker with the salt and sand in it.
Stir the water, sand, and salt gently with a glass stirring rod.
Remembering that Homogeneous mixtures are the same throughout and
Heterogeneous mixtures are different throughout, record your answers below:
4. What type of mixture did you form inside the beaker you stirred? (Circle your answer)
A Homogeneous Mixture
A Heterogeneous Mixture
Record what the mixture looks like inside the beaker :___________________
_________________________________________________________________
Procedure C: Analyzing a Mixture – “Separating Several Substances:”
1.
2.
3.
4.
Properly fold the filter paper and place it into your funnel. (Taco, pizza, sno-cone)
Place the filter & funnel over the remaining empty beaker.
Pour the mixture into the funnel, its okay if some of the sand is still in the beaker!
Examine the filter paper.
 Can you see both salt and sand on it? (circle one)
YES
NO
 Do you think there is still salt in the water? (circle one) YES
NO
 Without tasting, how could you find out if there is salt in the filtered water?
_______________________________________________________________
5.
Place 5 drops of the filtered water from your beaker onto a watch glass.
 Do you think the mixture in the beaker still contains salt? YES
6.
Using the tongs, carefully place the watch glass onto the hot plate. Let the liquid
water vaporize to gas, if anything is left you will see it on the glass.
 Do you see something on the watch glass? (circle one)
7.
NO
YES
NO
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this point,
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 Are the salt crystals the same shape they were in procedure A?
__________________________________________________________________
Procedure D:
1.
2.
Place a small scoop of iron files (Fe) and a scoop of Salt = Sodium chloride (NaCl).
in separate places on the bottom of the plastic Petri dish.
Use a hand lens to observe the two substances.
Write your observations – what does it look like?
Salt (NaCl): ______________________________________________
Salt (NaCl) is a(n):
Is Salt (NaCl) a pure substance?
ELEMENT
YES
COMPOUND
NO
Iron (Fe): ____________________________________________________
3.
Iron (Fe) is a(n):
ELEMENT
COMPOUND
Is iron (Fe) a pure substance?
YES
NO
Place the cover over the top of the petri dish. Then, shake carefully.
 What type of mixture did you make?
4.
5.
HETEROGENEOUs HOMOGENEOUS
Carefully bring a magnet over the cover of the petri dish. Slide the magnet back
and forth watching what happens. DO NOT LET THE MAGNET TOUCH
THE SUBSTANCES!!
 How was this mixture separated?
PHYSICALLY
CHEMICALLY
Did you separate the iron from the salt?
YES
NO
Did either element change chemically?
YES
NO
Conclusion Questions:
1.
a) What is a mixture? _________________________________________________
___________________________________________________________________
b) Describe what you did to make a mixture. ___________________________
__________________________________________________________________
2.
a) Describe one homogeneous mixture from this lab. _______________________
___________________________________________________________________
b) Why was it homogeneous? __________________________________________
___________________________________________________________________
3.
a) Describe one heterogeneous mixture in this lab. ________________________
__________________________________________________________________
b) Why was it heterogeneous? _________________________________________
__________________________________________________________________
4.
Other than from this lab, list some examples of each type of mixture:
Homogeneous mixture: a) _____________________ b)__________________
Heterogeneous mixture: a) _____________________
5.
b)__________________
How could you get drinkable water on a deserted island surrounded by saltwater.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
6.
In the containers below, draw an example of a heterogeneous mixture and a
homogeneous mixture. Use different colors, sizes, shapes, to represent the
particles in your mixtures. Be sure to label each mixture!