Question

Which of the following phosphorus is the most reactive?
A. Red phosphorus
B. White phosphorus
C. Scarlet phosphorus
D. Violet phosphorus

Answer 1

Hint: We know that there are different allotropic forms of phosphorus present in nature. The important allotropic forms of phosphorus are black phosphorus, white phosphorus, and red phosphorus. Among them, white phosphorus is the least stable, the most volatile, the most reactive, the least dense, and the most toxic allotropic forms of phosphorus. Also, it gradually changes to red phosphorus, a transformation that is accelerated by heat and light.

Complete step by step answer:
We have observed that white phosphorus is a translucent waxy solid that quickly becomes yellow when exposed to light. Due to this, it is also known as yellow phosphorus. It glows greenish in color in the dark when it is exposed to oxygen. It is highly flammable and pyrophoric and self-igniting when it comes in contact with air. The odor of combustion has a characteristic garlic smell, and there are samples that are commonly coated with white "diphosphorus pentoxide”.
It consists of ${P_4}{O_{10}}$ tetrahedral with oxygen which is inserted between the phosphorus atoms and at their vertices. Also, white phosphorus is slightly soluble in water.
Thus, we can store it underwater. Indeed, it is safe from self-igniting property when it is submerged in water.
We know that it is soluble in oils, carbon disulfide, benzene, and disulfur dichloride. Therefore, we can conclude that white phosphorus is the most reactive.

Hence option B is correct.

Note: We need to note that the white allotrope is produced using several different methods. In the industrial process, the phosphate rock gets heated in a fuel-fired or electric furnace in the presence of silica and carbon. Also, elemental phosphorus is then liberated as a vapor and then it can be collected under the presence of phosphoric acid. Also, we know that white phosphorus is toxic in nature which is responsible for causing severe liver damage and phossy jaw from chronic ingestion or inhalation.