Making Crystals

                        

Blue crystals of Hydrated Copper Sulphate

Crystals are formed when a hot saturated solution is cooled. First we made a saturated solution of Copper Sulphate. We ground up the copper sulphate into a fine powder and added it slowly to 50mls of water at 60 degrees celsius, stirring all the time until it dissolved.We kept adding more until it wouldn’t dissolve. We checked the temputure regularly using a thermometer. We tied string to a pen and put the string dangling in the blue stuff. We covered it with paper towel using a rubber band and then put it on the shelf, where it cooled slowly for a few days. 

After a few days small crystals were formed on the string. We took the best crystal and used it to seed the next saturated solution of copper sulphate. 
After a few days this small seed crystal had grown into a large crystal of copper sulphate that you can see in the photograph.


By Finnian Martin & David McNicholas 2A3