ANS:A - nitrophosphate

The reaction of nitric acid and sulphuric acid with phosphate rock produces nitrophosphate. Explanation: Nitrophosphate fertilizers, also known as ammonium nitrophosphate or nitrophosphoric acid, are produced by reacting phosphate rock with a mixture of nitric acid (HNO3) and sulphuric acid (H2SO4). This process is commonly referred to as the nitrophosphate process. In the nitrophosphate process:

1. Phosphate rock (calcium phosphate) is treated with a mixture of nitric acid and sulphuric acid.
2. The acids react with the phosphate rock to form various water-soluble phosphate compounds, including monoammonium phosphate (MAP) and diammonium phosphate (DAP), along with calcium sulfate and other by-products.
3. The resulting mixture is processed further to separate and purify the desired nitrophosphate fertilizers.
4. Nitrophosphate fertilizers are typically granulated for ease of handling and application in agriculture.

Nitrophosphate fertilizers are valued for their ability to supply multiple essential nutrients to plants, including nitrogen and phosphorus, in a single product. They are commonly used in crop fertilization to promote healthy growth and improve yields. Therefore, the reaction of nitric acid and sulphuric acid with phosphate rock is essential for the production of nitrophosphate fertilizers.