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Which of the following is used in the manufacturing of safety matches?
Red phosphorus
White phosphorus
Sulfur
Potassium chlorate
Red phosphorus
Red phosphorus is specifically used in the manufacturing of safety matches, coated on the striking surface of the matchbox along with powdered glass. Unlike highly reactive and toxic white phosphorus, red phosphorus is stable at room temperature and only reacts when subjected to the frictional heat of striking.
Red phosphorus is specifically used in the manufacturing of safety matches, coated on the striking surface of the matchbox along with powdered glass. Unlike highly reactive and toxic white phosphorus, red phosphorus is stable at room temperature and only reacts when subjected to the frictional heat of striking.
Striking a match is similar to rubbing two sticks together to generate localized frictional heat that triggers a larger fire.
Red on the side, ready for the ride (red phosphorus on the side of the box).
2KClO3тАЛ╬ФтАЛ2KCl+3O2тАЛ тАФ thermal decomposition of potassium chlorate
P4тАЛ+5O2тАЛтЖТ2P2тАЛO5тАЛ тАФ combustion of phosphorus
When a match is rubbed against the abrasive striking surface, the friction generates enough heat to convert a minute quantity of red phosphorus into white phosphorus. This reactive white phosphorus then initiates an exothermic reaction with the potassium chlorate present in the match head, causing combustion.
Safety match heads contain potassium chlorate and antimony trisulfide.
The striking surface contains red phosphorus and powdered glass for friction.
White phosphorus is not used directly due to its extreme toxicity and spontaneous flammability.
Red phosphorus is stable, non-toxic under normal conditions, and does not ignite spontaneously in air.
Requires specialized application on the striking surface rather than being mixed entirely into the match head.
Manufacturing of safety matchboxes
Pyrotechnics and chemical synthesis
White phosphorus spontaneously ignites in air at around 30 degrees Celsius and causes occupational poisoning known as phossy jaw.
Option C (Sulfur) and Option D (Potassium chlorate) are components of the match head composition rather than the striking strip.
A is correct тАФ Red phosphorus is used on the striking surface of safety matchboxes to facilitate safe ignition upon friction.
Remember that allotropes like red and white phosphorus have vastly different physical and chemical reactivities despite being composed of the exact same elemental molecules.