Crystallization cooling?

Question

After heating a dilute copper sulphate solution, it becomes saturated. Why must it be cooled down first before crystals appear? Why dont the crystals appear immediately once it is removed from the flame. Serious answer only. Thanks

Answer 1

Have you heard of water of crystallization?

If the copper sulphate solution is not cooled, there would not be any water of crystallization. Without the water, you would not see the crystal. The formula of your copper sulphate crystal is at CuSO4.5H2O or a certain amount of H2O. After heating directly, no water is being attached, no crystal is being formed.