NPK

• NPK fertilisers are formulations of different salts that contain required elements needed by plants
• phosphoric acid with nitric acid produces phosphoric acid and calcium nitrate. this acid contains phosphorus but cannot be added directly to plants so it needs to be neutralised
• phosphate rock with sulfuric acid can produce a mixture of calcium phosphate and calcium sulfate = single superphosphate= used in NPK F
• phosphate rock with phosphoric acid = triple superphosphate
• ammonium nitrate->ammonia + nitric acid
• ammonia is toxic and corrosive so in school labs we we would use dilute solutions and produce small amounts of ammonium nitrate