Q1: P₂O₅ content in superphosphate is about __________ percent.

ANS:B - 15-20

Superphosphate is a type of phosphatic fertilizer produced by reacting phosphate rock with sulfuric acid. During this reaction, phosphoric acid is formed, which then reacts further with the remaining phosphate rock to form calcium sulfate and various phosphates, including monocalcium phosphate. The P2O5 content in superphosphate typically ranges from 15 to 20 percent. This percentage represents the amount of phosphorus pentoxide (P2O5) present in the fertilizer. Phosphorus pentoxide is used as a convenient way to express the phosphorus content in fertilizers. Superphosphate is considered a moderately concentrated phosphatic fertilizer, with a lower phosphorus content compared to other phosphatic fertilizers like triple superphosphate. However, it is still widely used in agriculture to provide phosphorus, an essential nutrient for plant growth and development.