How to ignite zinc with just a drop of water ("Negative X")
This explosive detonates from a waterdrop
Wear protective gloves, a mask, and safety glasses. Conduct this experiment in a well-ventilated area. The reaction mixture is very sensitive to moisture and is too dangerous to store.
Reagents and equipment
- 8 g of zinc powder;
- 8 g of ammonium nitrate;
- 1 g of ammonium chloride;
- a beaker;
- a stirring rod;
- a pipette;
- a fireproof workspace
In the beaker, thoroughly mix 8 g of zinc powder, 8 g of ammonium nitrate, and 1 g of ammonium chloride. Pour the mixture out onto a fireproof surface and add a drop of water. The mixture will burst into a whirlwind of smoke and blue-green flame!
A mixture of zinc powder, ammonium nitrate, and ammonium chloride is often called “Negative X.” Adding just a small drop of water initiates a redox reaction, which is sped up by the presence of chloride ions. Being a strong reducing agent, zinc reacts explosively with nitrate ions to produce zinc oxide, nitrogen, and water:
NH₄NO₃ + Zn = ZnO + N₂ + 2H₂O