About a year ago, I found this Pyrophoria video that described how copper is used in pyrotechnics. Toward the end of the video, I learned that this mysterious compound known as copper ammonium chloride could make wood burn with an intense blue flame if the wood is soaked in a solution of the copper ammonium chloride.
I wanted to find out if it was true that this compound could cause such a beautiful flame, so therefore I decided to make some copper ammonium chloride of my own. The only problem was that the directions given stated that you needed to use hydrochloric acid, which is a highly reactive, and quite dangerous, acid, therefore, I have been avoiding the synthesis of this compound — that is, until I came to a sudden realization: why use a dangerous acid to synthesize the compound when I can use decently safe reactants?
Previously, I had come up with a method of producing copper chloride — a key component in the synthesis of copper ammonium chloride — using relatively safe ingredients. Here is the balanced reaction:
CuSO4 • 5 H2O (aq) + CaCl2 • 2 H2O (aq) -> CuCl2 • 2 H2O (aq) + CaSO4 • 2 H2O (s) + 3 H2O (l)
Now that I found a way to safely and cheaply produce copper chloride without using dangerous hydrochloric acid or expensive copper oxide, I only had one step left: add ammonia.
When I first added some ammonia to my copper chloride, I was quite surprised to see that no copper ammonium chloride was produced, instead, some type of precipitate was formed. After some research, I discovered that this “ammonia” was not actually ammonia (NH3), it was a solution of ammonium hydroxide (NH4OH).
The copper chloride reacted with the ammonium hydroxide to form ammonium chloride and copper hydroxide (the precipitate). I also learned that when more ammonia was added, the ammonia eventually dissolved the copper hydroxide, producing a very deep blue solution of copper ammonium chloride.
I was truly surprised by the intensity and hue of the copper ammonium chloride. It also appears to produce some decently blue flames according to my small scale tests, which is due to the fact that the copper ammonium chloride contains both copper and chlorine — the ideal ingredients for blue fire.
Do you have any thoughts on copper ammonium chloride?
Onward American 