Warning: Hydrochloric acid is corrosive and copper salts are toxic in large doses. Wear gloves when handling it. Greetings fellow nerds. I’ve gotten a lot of requests for this so in this video we’re going to make copper chloride. A useful chemical to etch copper clad printed circuit boards. And i’ll show three ways of doing it. The absolute simplest but slowest method is to get some copper metal and cover it with hydrochloric acid. Then bubble air through it. What’s happening is the oxygen in the air is reacting with the copper and hydrochloric acid to produce copper chloride. The problem with this method is that it’s very slow and takes a few days to start up. It gets faster once there is a lot of copper in solution but even then you need to be patient. A second way which is much faster is to get some copper. I’m using about 30 grams. Add some hydrochloric acid to cover it and then add an equal volume of 3%-6% hydrogen peroxide. In this case i’m using 200 ml for both. Stirring also helps to react the copper. What’s happening is the hydrogen peroxide directly oxidizes the copper and reacts with hydrochloric acid to produce copper chloride. This is much faster and just takes a couple of hours to finish. The third way is for those of you that don’t mind some sulfate contamination in your copper chloride. First start with copper sulfate and just keep adding hydrochloric acid with stirring until all the copper sulfate dissolves. Be sure to give it some time between hydrochloric acid additions as copper sulfate can dissolve very slowly. Anyway, while this solution of copper chloride also contains sulfate ions, it can still be used for PCB etching and gold recovery procedures as the sulfate ions do not interfere in those cases. So this can be a very convenient method to get the benefits of copper chloride if all you have is copper sulfate and hydrochloric acid. Now however you make your copper chloride, you can test its potency by dipping a piece of copper clad printed circuit board. If the board etches clean, then you’ve successfully made copper (II) chloride. If it doesn’t you might have large amounts of copper (I) chloride or simply not enough copper at all. Try reacting it with more air or hydrogen peroxide. Anyway, that’s how you make copper chloride. Thanks for watching.