Effect of Heat on Crystals


To study the effect of heat on crystals.

Materials Required

  1. Test tubes
  2. Delivery tube
  3. Retort stand
  4. Bunsen burner
  5. Beaker
  6. Copper sulphate crystals
  7. Common salt
  8. Epsom salt
  9. Glauber's salt
  10. Cobalt chloride
  11. Potassium nitrate
  12. Washing soda
  13. Potassium chlorate


effect of heat on crystals

Effect of Heat on Crystals Science Fair Project

Heat each of the salts listed above in a dry test tube carrying a delivery tube. Insert the delivery tube in another test tube cooled in a beaker of cold water. Collect the condensed liquid and identify it by placing a drop of it on white copper sulphate powder. The test for water is that it turns white anhydrous copper sulphate blue.


The clear liquid turns white anhydrous copper sulphate blue. A few of the salts do not give this liquid, most of them do. Salts that give out water of cystallisation on heating are copper sulphate, Epsom salt Glauber's salt, washing soda & cobalt chloride. Salts that do not give out water of crystallisation are common salt, potassium nitrate & potassium chlorate.


This clear liquid which certain crystals of salts contain and give out on heating is water. It is called water of crystallisation. Thus, there are two types of crystalline salts: those that contain water of rcystallisation and give it out on heating and others which do not.