General Science and Biology: Making Crystals

This week we continued our investigations of solutions by making and examining crystals under the microscope. First we made saturated solutions of salt, copper sulfate, and borax. Then we placed a drop of each on a microscope slide, put them outside and waited for them to evaporate, and then used a microscope to look at the crystals that remained.

Pretty cool, but not nearly as cool as the rock candy we prepared. On paper, a very simple operation: Make a really saturated solution of sugar water (3:1) ratio. Heat it on the stove. Then pour it into a jar that has a string suspended inside. Wait a week, and voilà, you've got rock candy. In practice though, it's very messy, sticky, with an extremely low yield. We observed that using a pipe cleaner will produce better crystals because of the increased surface area, but then you might also get brightly colored crystals that not so mysteriously match the color of the pipe-cleaner.