Making Basic Copper Sulphate Using Electrolysis II


4. Create the Basic Copper Sulphate acid solution. Add […]

4. Create the Basic Copper Sulphate acid solution. Add 30ml of water to the beaker, and 5ml of concentrated sulfuric acid. If you are using the less concentrated battery solution, add 15ml of acid to 20ml of water.

5. Set the two wires in the solution so that they are not touching each other. The wires should be an inch or so apart, depending on the size of your container, and should not be touching each other.

6. Connect the wires to the 6-volt battery. One wire should be wrapped around the positive terminal, and one should be wrapped around the negative terminal.

7. Watch the reaction take place. You should see a bubble forming at the anode (the wire connected to the negative terminal) but not the cathode, and the solution will begin to turn blue as the copper sulfate is formed. Let the reaction run until the solution is quite blue, and then remove the wires from the solution and disconnect them from the battery.

8. Evaporate the solution to recover the crystals. You can evaporate the solution by pouring it into a shallow glass dish that is exposed to the air for several days. You can also speed the process up by boiling the solution carefully in a heat-resistant (pyrex or borosilicate) pan and then pouring off the last bit of sulfuric acid that does not evaporate. Be careful, as the solution in question is caustic and should be handled with great care.

9. Dispose of excess copper sulfate solution correctly. Copper sulfate is toxic to fish, plants, and other wildlife and should not be poured into lakes or streams, or rinsed down the storm drain. Copper sulfate is a common ingredient in many drain cleaners, and small quantities, like what this experiment will yield, can be safely diluted with water and rinsed down the sink.