cools, it cannot dissolve as much solute. If the solution cools very slowly the molecules of copper sulfate have time to come together and form larger crystals. If it cools very quickly the large crystals do not have time to form and instead tiny crystals settle at the bottom of the evaporating dish.
Activity Grow copper sulfate crystals
Apparatus and chemicals used Two beakers, tongs, evaporating dish, Bunsen burner, tripod and gauze, heat-proof mat, copper sulfate and water
Fig. 2 Heating the evaporating dish.
Fig. 3 Heating the copper sulfate solution.
Method 1. One-quarter fill a beaker with water and place an evaporating dish over the top. 2. Heat the evaporating dish by placing the beaker on a gauze over a Bunsen burner. 3. When the evaporating dish is hot, carefully remove the beaker and evaporating dish from the heat using a tongs and stand it on a heat-proof mat.
4. One-quarter fill another beaker with water. Add copper sulfate until no more will dissolve (a saturated solution).
5. Heat this solution gently until steam is visibly rising. 6. If all the copper sulfate has dissolved add a little more and stir carefully. 7. Pour the hot solution of copper sulfate into the warm evaporating dish. 8. Allow this to cool slowly for several hours or days in a place where it will not be disturbed.
9. Examine (but do not handle) the crystals formed.
Question How would you change the experiment to grow small crystals?
