Growing Crystals from Solutions
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Delores E. Jackson Richard Byrd School
363 West Hill Street
Chicago, Illinois 60610
Forming crystals in three-dimensional patterns from solutions.
(1) Sugar (C12H22O12)
(2) Potassium sulfate (K2SO4)
(3) Epsom salts (magnesium sulfate - MgSO4)
(4) Baking soda (sodium bicarbonate - NaHCO3)
(5) Sodium ferrocyanide (Na4Fe(CN)6.10H2O)
(6) Ammonium ferric sulfate (NH4Fe(SO4)2.12H20)
(7) Eight large test tubes with one-hole stoppers to fit
(8) Eight circles of copper wire
(10) Hot water
(11) Hand lens or magnifying glass
(1) Fill the first test tube with hot water. Add the sugar, a small amount at a
time, and stir with a glass stirring rod until no more sugar dissolves.
(2) Tie a six inch piece of thread to a circle of copper wire. Pass the other
end of the thread through the hole of a one-hole stopper to fit the test
(3) Put the copper wire in the sugar solution and insert the stopper in the
tube. Adjust the length of the thread so that the copper wire is about
0.5 in. from the bottom of the test tube. Hold the thread in place by taping
it to the stopper with a small piece of masking tape. Keep the hole in the
(4) Set the tube aside where it will be undisturbed for 3 or 4 days.
CAUTION Sodium ferrocyanide is poisonous, so be extremely careful when
conducting this experiment. Suggested powders for Primary grades; soda, epsom
salt, salt, sugar.
(5) Repeat the procedure with the following chemicals: potassium sulfate
ammonium ferric sulfate, magnesium sulfate (Epsom salts), sodium bicarbonate
(baking soda), and sodium ferrocyanide. Add each chemical to a tube half
filled with hot water and stir until no more solid will dissolve. Be sure to
label each tube.
(6) After crystals have formed on each string, carefully remove each string from
its tube and describe the crystals.
(7) To help you describe the shape of each crystal, model patterns are provided.
Cut out each model and fold it into the proper shape. These six geometric
shapes represent some of the basic structures found in crystals.
(8) Using these models as a guide, examine each crystal with a small hand lens
or magnifying glass and describe completely each crystal, including its
size, color, clarity and shape. Compare your results with those of your