Question

What is meant by superphosphate of lime? Give its composition.

Short answer

Answer: Superphosphate of lime is a fertilizer created by treating rock phosphate with sulfuric acid. It provides essential nutrients like phosphorus and calcium to plants and is used to promote root development and flowering. The composition mainly consists of monocalcium phosphate (16-20%), calcium sulfate (12-15%), unreacted rock phosphate (2-5%), and trace elements and impurities such as iron, aluminum, and fluoride.

Step-by-step solution

Definition of Superphosphate of Lime

Superphosphate of lime is a type of fertilizer created by treating rock phosphate with sulfuric acid. It provides essential nutrients like phosphorus and calcium to plants, and it is used to promote root development and flowering.

Composition of Superphosphate of Lime

The composition of superphosphate of lime mainly consists of: 1. Monocalcium phosphate (Ca(H_2PO_4)_2): This compound is responsible for providing phosphorus, which is an essential nutrient for plant growth, root development, and seed formation. It typically comprises about 16-20% of the total composition. 2. Calcium sulfate (CaSO_4): Also known as gypsum, this compound provides calcium and sulfur essential for plant growth and development. Calcium sulfate usually makes up about 12-15% of the composition. 3. Unreacted rock phosphate: Some rock phosphate remains unreacted in the process of making superphosphate of lime, and it makes up about 2-5% of the composition. 4. Other elements: The remaining part of the composition includes trace elements and impurities such as iron, aluminum, and fluoride. The percentages of these elements vary, but they generally make up a small portion of the total composition.