What substances were used in the head of early matches to initiate combustion?
I. Antimony trisulphide
II. Potassium chlorate
III. White phosphorus
Show answer & explanation
Correct answer: D
Explanation
Correct Answer: Option 4 (I, II, and III)
Explanation:
Early matchsticks used various chemical substances for ignition, including antimony trisulfide, potassium chlorate, and white phosphorus. These substances ignite easily and, through friction, produce flame, which ignites the match.
Additional Facts:
White phosphorus is highly flammable and toxic, so it was later replaced by the safer alternative, red phosphorus.
Modern matches use red phosphorus, which is less dangerous.
Potassium chlorate acts as an oxidizing agent.
Possible Questions for the Upcoming Exam:
Which is the safe phosphorus used in matchsticks?
(Answer: Red phosphorus)
What is the function of potassium chlorate?
(Answer: As an oxidizing agent)
Why was white phosphorus replaced?
(Answer: It is toxic and highly flammable)