When phosphate rock is treated with nitric acid (often with associated sulfuric acid steps in some flowsheets), the resulting fertilizer product is classified as:

Introduction / Context:
Nitrophosphate processes, such as the Odda route, digest phosphate rock with nitric acid to produce a solution containing calcium nitrate and phosphoric species, which is then further processed to yield N–P or N–P–K fertilizers. Some variants introduce sulfuric acid for calcium removal steps, but the defining acidulation is with nitric acid. Knowing the correct product classification distinguishes nitrophosphate chemistry from sulfuric-acid superphosphates and ammoniated phosphates.

Given Data / Assumptions:

• Starting material: phosphate rock.
• Main acidulant: nitric acid (HNO3), possibly with auxiliary steps involving H2SO4.
• Product family: fertilizers that contain nitrogen and phosphorus together.

Concept / Approach:
Reaction of phosphate rock with nitric acid yields a mixed nutrient liquor that, after neutralization and finishing, gives nitrophosphate. This is a complex fertilizer where N and P are present within the same granule matrix. Diammonium phosphate (DAP) instead results from ammoniating phosphoric acid, not nitric acid. Tricresyl phosphate and tributyl phosphate are organic esters, used as plasticizers or extractants, not bulk fertilizers.

Step-by-Step Solution:
Identify acidulant as HNO3 → characteristic of nitrophosphate route.Recognize combined N and P in final product → complex fertilizer.Exclude DAP (comes from NH3 + H3PO4) and organic phosphates (non-fertilizer chemicals).Select “Nitrophosphate.”

Verification / Alternative check:
Industry references list nitrophosphate products under trade names produced by nitric acid digestion followed by controlled neutralization and granulation steps.

Why Other Options Are Wrong:
Diammonium phosphate: manufactured from phosphoric acid and ammonia, not nitric acid digestion of rock.Tricresyl/tributyl phosphates: organic chemicals, not fertilizers.

Common Pitfalls:
Confusing nitrophosphate (HNO3 route) with superphosphates (H2SO4 route) and with ammoniated phosphates (H3PO4 + NH3).

Final Answer:
Nitrophosphate