Question

Which of the following process occurs when red phosphorus is heated under high pressure?

• A. Red Phosphorus will convert to white phosphorus
• B. Discrete tetrahedral molecule of $P_4$ will be formed
• C. Series of phases of black phosphorus will be formed
• D. Product obtains readily oxidizes in air

Answer 1

The correct option is C Series of phases of black phosphorus will be formed

Red phosphorus is more stable than white phosphorus and it is prepared by heating white phosphorus(discrete $P_4$ molecule) in an inert atmosphere.
When red phosphorus is heated a series of phases of black phosphorus is formed which does not react with air upto 673 K