Difference in Ionic Crystal Compounds

¶ … Ionic Crystals In these two labs, I investigated table salt crystals and Epsom salt crystals and found that these two different types of salt produced two different types of crystals. These labs were conducted by following the procedures recommended by the About.com websites related to chemistry and ionic crystals. For table salt crystals, I used the website http://chemistry.about.com/od/growingcrystals/ht/saltcrystals.htm and for growing Epsom salt crystals http://chemistry.about.com/od/crystalrecipes/ht/cupofcrystals.htm. Materials used in the two labs were similar.

For the table salt lab, I used table salt (or sodium chloride), boiling water, a glass jar, and a seed crystal. For the Epsom salt lab, I used a small bowl, Epsom salt and hot water from the tap (not boiling). Because different salts and different crystals were being formed, the procedures were, naturally, a bit different. For the table salt crystals, I first boiled a pot of water, and then I poured some of it into a jar and stirred in the table salt until it was all dissolved.

Next, I took my seed crystal, which I made by letting the salt-water solution evaporate in a small dish. As the solution evaporated, crystals formed. I chose a cubic looking crystal, which looked like a salt cube, as my seed crystal. I tied this crystal to a small stick, which I balanced over top the jar with the new solution in it.

I let the seed crystal hang in the solution and covered the top of the jar with a cloth so that no flies or dust could fall into the jar. Then I put all of this in the shade on a shelf where it could rest and not be disturbed. Crystals began to form on the seed crystal and the string after a few hours. These crystals were small and somewhat cloudy in appearance.

The seed crystal had been smooth and somewhat less cloudy (which is why I chose it), but with the new crystals formed on it and the string, it had the overall appearance of a rock candy like substance. The crystals were small, both roundish and cubic, like rough squares or spheres. The Epsom salt crystal procedure was even simpler. I mixed a half cup of Epsom salt (or magnesium sulfate) in a half cup of hot water from the tap in a small bowl.

After stirring to dissolve the salt, I put the bowl in the fridge and left it alone for four hours. At the end of this time, I took out the bowl and examined the crystals: they had formed like a nest of long pine needles in the bowl. This formation was much different from the table salt crystal.

These crystals were long and thin and cylindrical and seemed to wad up with one another as though someone had taken all the needles and crunched them into a big need crystal ball. These needles were also less cloudy than the table salt needles.

They had a much more glassy appearance and looked more like a crystal than the table salt, which still actually looked like table salt, just in larger unrefined clumps, typical of what you would find were you to buy unrefined table salt from the store or distill your own from the sea. In conclusion, it may be stated that these two crystal formations were different because of the type of salt used and also perhaps because of the cooling procedures.

The table salt crystals were formed through a procedure of slow cooling and.