How Do Pop Its Work? Chemistry of Bang Snaps

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Pop Its or Party Snaps
Pop Its or Party Snaps are small novelty fireworks that make noise when thrown against a hard surface.

Pop Its belong to a class of novelty fireworks or toys called bang snaps. The snaps go by many names, including poppers, party snaps, bang snaps, snappers, throwdowns, Pop Its, and Snap-Its. Pop Its are noisemakers that don’t cause physical damage when they pop, even if used in a person’s hand. Snappers first came into use as toys when Tom Smith invented the Christmas cracker in 1847. Pop Its and other bang snaps are popular for New Years, Memorial Day, 4th of July, and Christmas celebrations.

How Pop Its Work

Decomposition of silver fulminates produces the popping sound of pop its or snaps.
Decomposition of silver fulminates produces the popping sound of Pop Its or bang snaps.

“TNT” is one popular brand of Pop Its, but bang snaps don’t contain any TNT (trinitrotoluene)! Pop Its consist of a tiny amount of silver fulminate (0.08 to 0.20 milligrams) with coarse sand or gravel (200 milligrams), twisted into tissue paper or cigarette paper. When the device is thrown, stepped on, or burned, it produces a sharp popping sound. The sand buffers the shock wave, so the explosion doesn’t cause harm. Sometimes silver fulminate is combined with 10-20% potassium chlorate to make the mixture more pressure-reactive and also cheaper.

Are Pop Its Safe?

Pop Its and other bang snaps are considered safe. Even when a large number are thrown or crushed at once, they don’t cause physical harm or pose a fire hazard. In some locations, Pop Its and Christmas crackers (a comparable product) are considered safe for use by children. However, some U.S. states and countries have age restrictions for bang snap purchase. In the UK, fun snaps may only be purchased by people age 16 or older. Elsewhere, if there is an age limit, it’s usually 17 or 18.

How to Deactivate Pop Its

Of course, the fun way to deactivate Pop Its is to throw them. But, you can decompose the silver fulminate without getting the “pop,” using either thiosulfate or hydrochloric acid.

Fun Pop Its or Bang Snap Facts

Each pop it or snap is very small, so although it explodes it only produces noise and does not cause physical harm.
Each Pop It or snap is very small, so although it explodes it only produces noise and does not cause physical harm. (William “willster3” Carpenter)
  • Snap bangs work in water!
  • The silver fulminate in Pop Its is highly stable. It will not decompose, even after many years.
  • You can extract pure silver metal from Pop Its. To do this, pop all of the snaps and burn away the paper. This leaves gravel, ash, and the silver compound. Mix a bit of dilute nitric acid. Save the liquid, rinsing the gravel with water to recover as much silver as possible. Precipitate the silver to form silver chloride and heat the result to get silver metal (plus whatever metal you used to get the chloride). It’s a fun chemistry project, but not an economical project, since you get about 50 cents worth of silver out of $50 of snaps.
Here’s how to get the silver out of pop its or bang snaps.

How to Make Pop Its Yourself

It’s incredibly easy to make homemade Pop Its. All you do it react silver metal with concentrated nitric acid to make silver fulminate. The only tricky part of the process is filtering the solid silver fulminate out of the liquid without accidentally detonating it. Silver fulminate is pressure-sensitive, shock-sensitive, heat-sensitive, electricity-sensitive, and active in water. Even the weight of silver fulminate crystals on top of each other can cause them to explode.

So, you can add corn starch or flour to the mixture when filtering it to provide a cushion for the silver fulminate crystals. Finally, wrap a tiny amount of silver fulminate with a bit of coarse sand with tissue paper to make snaps.

Another way to make silver fulminate is to pour a solution of silver nitrate in nitric acid under slightly warm conditions (80-90 °C to force precipitate formation).

Other methods to make silver fulminate are reacting silver carbonate with ammonia, bubbling nitrogen gas through a solution of silver nitrate in ethanol, or reacting silver nitrate solution with alcohol. Sometimes the reaction is unintentional, as when silvering mirrors or holiday ornaments.

References

  • Collins, P. H.; Holloway, K. J. (1978). “A Reappraisal of silver fulminate as a detonant”. Propellants, Explosives, Pyrotechnics. 3 (6): 159–162. doi:10.1002/prep.19780030603
  • International Union of Pure and Applied Chemistry (2005). Nomenclature of Inorganic Chemistry (IUPAC Recommendations 2005). Cambridge (UK): RSC–IUPAC. ISBN 0-85404-438-8.
  • Matyas, Robert; Pachman, Jiri (2013). Primary Explosives. Springer Science & Business Media.
  • Singh, K. (1959). “Crystal structure of silver fulminate”. Acta Crystallographica. 12 (12): 1053. doi:10.1107/S0365110X5900295X