describe the process of formation of copper sulphate crystals .
Answers
Ans: To prepare crystals of copper sulphate.
Required items: China dish, Glass rod, Wash bottle, Copper sulphate, Burner, 250 ml beaker, Wire gauze, Tripod stand, water
Method
1. Take a clean beaker (250 ml) and put the powdered sample of copper sulphate in it. Add distilled water and stir well using glass rod.
2. Make the solution more clearly by adding 2 – 3 drops of concentrated sulphuric acid in it and heat up 70° C then add more impure copper sulphate until no more of it dissolves.
3. Filter the solution and collect the filtrate in a china dish heat it over wire gauze kept on tripod with proper stirring to get constant temperature till it becomes half of the taken, cool the other end of glass rod by blowing air.
4. Formation of thin crust indicates that crystallization points is reached, then turn off the burner and cover it with a watch glass without disturbing it. As the solution cools down, crystals separate out. Slow cooling ensures for better crystallization.
5. Decant the mother liquor and wash the crystals with a thin stream of cold water with the help of a wash bottle press these between filter paper sheets. Then blue colored copper sulphate crystals will be formed.