ANS:B - 52-54

Triple superphosphate, which typically contains about 46% P2O5, is produced by the reaction of phosphate rock with orthophosphoric acid of 75-80% concentration. Explanation:

1. Production Process: Triple superphosphate (TSP) is manufactured through the reaction of phosphate rock (apatite) with concentrated orthophosphoric acid. This reaction is commonly known as the superphosphating process.
2. Orthophosphoric Acid Concentration: The orthophosphoric acid used in the production of TSP is typically highly concentrated, ranging from 75% to 80% concentration. This high concentration ensures efficient and thorough reaction with the phosphate rock.
3. Reaction: In the reaction between phosphate rock and orthophosphoric acid, phosphoric acid is formed. This phosphoric acid then reacts further with more phosphate rock to form triple superphosphate, which contains higher levels of available phosphorus compared to single superphosphate.
4. Phosphorus Content: Triple superphosphate typically contains around 46% P2O5 (phosphorus pentoxide) by weight. This high phosphorus content makes it a valuable phosphatic fertilizer for agricultural use.
5. Importance: TSP is widely used in agriculture to provide readily available phosphorus to plants, promoting root development, flowering, and fruiting. Its production process involves carefully controlled reactions to ensure the desired phosphorus content and nutrient availability in the final product.