Question

How do matchsticks work? Explain the compounds used and their function.

Answer 1

The match heads of safety matches contain sulfur (sometimes antimony III sulfide) and oxidizing agents (usually potassium chlorate), with powdered glass, colorants, fillers, and a binder made of glue and starch. The striking surface consists of powdered glass or silica (sand), red phosphorus, binder, and filler.

1. When you strike a safety match, the glass-on-glass friction generates heat, converting a small amount of red phosphorus to white phosphorus vapor.
2. White phosphorus spontaneously ignites, decomposing potassium chlorate and liberating oxygen.
3. At this point, the sulfur starts to burn, which ignites the wood of the match. The match head is coated with paraffin wax so the flame burns into the stick.
4. The wood of a match is special, too. Match sticks are soaked in an ammonium phosphate solution that reduces afterglow when the flame goes out.

Match heads are commonly red. This isn't the natural color of the chemicals. Instead, red dye is added to the tip of the match to indicate it's the end that catches on fire.