Question

This lab illustrates how supersaturated solutions are prepared, and the process of crystallization. This lab can be done with a number of different salts. You will need to allow your solutions to sit for at least three weeks. This is one way to make rock candy. Be SURE to start this lab with plenty of time to finish. Materials -string -pencils -glass drink bottles -various salts (choose from the following list.) -table salt, sodium chloride -alum -baking soda -copper sulfate -sugar ( not a salt, but it does make pretty crystals) Epson's salts Procedure: Perform this procedure with sugar and any two other solids from the list above. You will need one bottle for each solid you make crystals with. 1. Pour a clean glass drink bottle of water into a microwaveable bowl and dissolve as much sugar or other solid as you can at room temperature. Warm the solution and keep adding sugar or other solid until no more will dissolve. At this point you will have prepared a supersaturated solution. 2. While the solution is still warm, pour it back into the clean glass drink bottle. 3. Tie string around a pencil so that about 4 inches of the string dangles from the it. 4. Place the pencil over the mouth of the bottle so that the string hangs in the solution. 5. Set your bottles of supersaturated solutions aside in an area where they will not be disturbed for at least one week. 6. After a week, lift the string out of the solution and observe the crystal formation. Take a digital picture of each solution's crystals. 7. Allow the bottles to sit for another week and take pictures of the crystals again. 8. After a third week check to see how much your crystals have grown. You can continue allowing the solutions to sit and grow larger crystals for longer if you want to see just how big they can get. You lab report should discuss the differences between unsaturated, saturated and supersaturated solutions. Describe what you did, what you saw, and the meaning of your observations. Be sure to include digital pictures that show the progressive growth of your crystals. AND make sure YOU are in at least one of these pics. This is a slow process, but your patience will be rewarded by some beautiful crystals. The copper sulfate crystals are a striking clear blue color.