1Crystallizing Minerals from Aqueous Solutions

compound	name	add to 200 cc H2O	
NaCl	halite	100 gm	
KCl	sylvite	100 gm	
K3Fe(CN)6	potassium ferricyanide	93 gm	
Cu(CH3COO)2∙H2O	cupric acetate	20 gm	
C12H22O11	sucrose	460 gm	
NaNO3	sodium nitrate	110 gm	
KAl(SO4)2∙12H2O	alum	40 gm	
KNaC 4H4O6)4H2O	Rochelle salt	260 gm	

equipment

400-ml beakers
water - pref. distilled
stirring rods
weighing papers

balance scale that goes to 500 gm
hot plate
thread
kimwipes & rubberbands
General Procedure

Part 1:

You will create supersaturated solutions by adding the powdered compounds to water in ratios specified.  The solutions will be heated and stirred until the solids have dissolved, and then  you will let the liquids cool, and cover them with a kimwipe held in place with a rubber band.  Then we will wait while they evaporate and see what crystals form.

Be sure to weigh the reagents to make sure you have enough for 200 cc of water.  If not, mix up a smaller batch in a smaller beaker.

For the sucrose, suspend a string in the mix to give it something to grow on.

Part 2 (to be done at least 3 weeks after part 1):

Look at the crystals we grew from the aqueous solutions.  Try to figure out what the “ideal” crystal shape is.  Make a sketch.  Describe the number and size of crystals you see.  And describe any other interesting features.