An every day item which depends on halogen chemistry is the match. When a match is struck, the chemical on the matchhead, potassium chlorate or KClO3, decomposes, giving O2 when heated in the presence of a catalyst:
2KClO3 2KCl + 3O2
This reaction occurs whenever a match is struck. The O2 produced helps ignite other components of the match head as well as the match itself. This reaction is shown in the video below:
In the video, KCLO3 is mixed with red phosphorus. It is then tapped with a hammer, resulting in an explosion. We already mentioned that the match head contains KCLO3. In this instance, red phosphorus coats the striking surface of the box. The friction of striking the match causes the reaction to occur in this case. The striking of a match is shown below. Though in a different context, it is clear both reaction are the same.