15
SJ #3 “Filtering a Solution”
Lesson 15
Read p. 122 together, discuss separation techniques of mixtures and solutions
Materials: *goggles
*test tube rack
*CuSO4
*3 test tubes
*ZnO
*3 cups
*rock salt
*lab scoops
*10 mL graduated cylinder
*3 filter papers
*1 stick
*3 funnels
*water
Data Table: Copy the following data table into your SJ.
Substance
Observations
Before Filtering
Predictions
What will you see
after you filter the
mixture?
Actual Observations
What DO you see
after you filter the
mixture?
A) CuSO4
B) ZnO
C) rock salt
Procedure:
1) Bring your 3 CUPS up to the front cart:
A) Pour about 10 mL of CuSO4 into cup A.
B) Add 1 scoop of ZnO to a second cup B.
C) Add 1 scoop of rock salt to a third cup C.
D) Add 10 mL of water to cups B + C and stir with the stick.
Write down your observations of the mixtures BEFORE filtering
in the data table.
2) Before filtering each mixture, PREDICT what will happen after you pour
each of these 3 mixtures through the filter paper. Record in the data
table:
A) CuSO4
B) ZnO
C) rock salt
3) Fold one piece of filter paper as instructed (Fig 15.1 p. 124) and put into
a funnel. Wet the paper with a few drops of water so it sticks to the
funnel walls.
4) Make sure your test tubes (A, B, + C) are in order on your rack.
5) Place your funnel/filter paper into test tube A. (see p. 125)
6) Pour a mixture of CuSO4 into test tube A through the filter paper.
Record your observations in the data table. Dispose of filter paper
and rinse your funnel.
7) Fold your second piece of filter paper and place it in the funnel. Pour a
mixture of ZnO into test tube B through a new piece of filter paper.
Record your observations in the data table.
8) Fold your third piece of filter paper and place it in the funnel. Pour a
mixture of rock salt into test tube C through a new piece of filter
paper. Record your observations in the data table.
9) Dispose of ALL mixtures properly in the slop containers and RINSE
YOUR CUPS AND TEST TUBES COMPLETELY, USE A SCRUB
BRUSH IF NEEDED. RETURN ALL MATERIALS.
Tape a copy of and answer these questions IN YOUR SJ:
1) Of the 3 mixtures used in the lab, classify each as: a mixture, a solution, or a
solution/mixture combination.
2) Does filtering a solution separate a solute from a solvent? What evidence is
there to prove your answer?
3) Does filtering a mixture separate the parts? What evidence is there to prove
your answer?
4) Is filtering an aqueous mixture a good procedure for getting pure water? Why
or why not?
5) You are given a mixture of water, sugar, and dirt. Describe how you would
separate the mixture so that you are left with pure sugar.