The most important mineral fertilizers
Nitrogen fertilizers: sodium saltpetre NaNO₃, potassium saltpetre KNO₃, ammonium nitrate NH₄NO₃ (ω(N) = 35 %), ammonium sulfate (NH₄)₂SO₄, urea CO(NH₂)₂ (ω(N) ≈ 47 %). Ammonium nitrate is made by acting on ammonia with nitric acid: NH₃ + HNO₃ → NH₄NO₃; it absorbs moisture and is dangerous with flammable materials, so it must be kept dry and separate. Phosphorus fertilizers: phosphorite meal (Ca₃(PO₄)₂, insoluble in water, for acid soils), simple superphosphate Ca(H₂PO₄)₂ · CaSO₄ (Ca₃(PO₄)₂ + 2H₂SO₄ → Ca(H₂PO₄)₂ + 2CaSO₄), double superphosphate Ca(H₂PO₄)₂ (Ca₃(PO₄)₂ + 4H₃PO₄ → 3Ca(H₂PO₄)₂, 40–50 % P₂O₅), precipitate CaHPO₄ · 2H₂O, bone meal, and the complex ammophos (a mixture of NH₄H₂PO₄ and (NH₄)₂HPO₄). Potassium fertilizers: KCl (52–60 % K₂O), sylvinite KCl · NaCl, kainite, potassium nitrate and plant ash (mainly K₂CO₃). The chlorine in sylvinite and kainite harms some plants, so the dose is not exceeded. Ammonium fertilizers are not put on limed soil, since ammonia escapes. Many fertilizers are produced at chemical plants in our country.
“Fertilizer table”: for 12 fertilizers make a table: name, formula, nutrient element, condition of use (e.g. not for limed soil), storage rule. Calculate the nutrient content for 3 of them. Only a book, notebook and calculator.