Burning paper towels soaked in various metal nitrates
Igniting paper towels that have been soaked in concentrated potassium nitrate and allowed to dry yields a flame reminiscent of that produced by guncotton. Repeating this experiment with other metal nitrates produces flames with different colors, plus a few other chemical surprises! This series of experiments is fascinating and connects to a wide variety of chemical topics including combustion, redox reactions, chemical thermodynamics, and flame tests. You don't want to miss this one!