Water Hypergol
Since I didn't have any pages about hypergols, I decided to put one up about this fun mix that ignites with water. It's the same one that some refer to as "Negative-X", but I never really liked that name. It's quite simple to mix up as it just requires ammonium nitrate, zinc dust, and a chloride salt like ammonium chloride. Today I mixed together 2.5 grams of zinc dust, 1 gram of ammonium nitrate, and 0.1 grams of ammonium chloride.
The reaction is initiated by water and the zinc in the mixture is oxidized while the ammonium nitrate decomposes. The chloride is a catalyst. All that's needed for a ignition is addition of a drop of water. The mixture is hygroscopic and poses the danger of autoignition. So don't store it. Warnings aside, this is pretty fun stuff. Once water is added the mixture will begun to bubble and then burst into a blue-green flame and produce smoke. You can see that happen in the following video, though the flame is a bit hard to see. The orange flame is from the paper underneath.
