Аммония дигидрофосфат

Химические свойства

Ammonium phosphate occurs in two forms-the monobasic, NH4H2P04, and dibasic,(NH4)2HP04, forms, It is a white crystalline solid that is soluble in water. Ammonium phosphate is a product of the reaction between ammonia and phosphoric acid.Ammonium phosphate is an important fertilizer and is used as a fire retardant

Физические свойства

Electrooptic coefficient (cm/stat-volt): γ₆₃=-2.54×10^-7, γ₄₁₌62×10^-7
Dielectric constants: ε₀=56.4–55.9 (10² –10⁸ Hz, E⊥C), 16.4–13.7 (10² –10 Hz, E//C).

Физические свойства

White crystalline powder; odorless; density 1.80 g/cm³; readily dissolves in water (40 g/ 100 g); pH of 0.2 molar solution 4.2; slightly soluble in alcohol; insoluble in acetone.

Использование

Ammonium dihydrogen phosphate is a general purpose food additive which is readily soluble in water. A 1% solution has a ph of 4.3–5.0. It is used as a dough strengthener and leavening agent in baked goods and as a firming agent and ph control agent in condiments and puddings. It is also used in baking powder with sodium bicarbonate and as a yeast food.

Подготовка

Preparative method similar to its dibasic salt; obtained by reaction of equimolar amounts of ammonia and phosphoric acid:
NH₃ + H₃PO₄ → (NH₄)H₂PO₄.

Определение

ChEBI: The ammonium salt of phosphoric acid (molar ratio 1:1).

Общее описание

Ammonium phosphate monobasic (APM) is an inorganic salt widely used in fertilizer, baking powder and yeast production. It is also employed as an agent to control pH of a solution and in corrosion inhibition. APM can be prepared by reacting phosphoric acid with anhydrous ammonia maintaining the pH below 5.8. The change in some of the physical characteristics on its addition to a high carbonate containing unfired and fired illitic shale has been studied.

Сельскохозяйственное использование

Ammonium phosphates refer to a generic class of phosphorus fertilizers and are manufactured by reacting anhydrous ammonia with orthophosphoric acid or superphosphoric acid. These are either in solid or liquid form.
Ammonium phosphate fertilizers are highly soluble in water and fast acting in soil to give nitrogen and phosphorus in a chemical combination. They form an important base for many compound fertilizers. Both mono and diammonium phosphates have good physical properties when synthesized from the wetprocess phosphoric acid. Storage properties and the ease of granulation depends on the amount of impurities, which form a gel like structure (mainly aluminum and iron phosphates). This gel promotes granulation and serves as a conditioner to prevent caking even at moderately high moisture levels. A small proportion of phosphate rock added to phosphoric acid before ammoniation improves the granulation.
Ammonium phosphates, particularly Ammonium dihydrogen phosphate(DAP), are the most popular phosphate fertilizers worldwide because of their high utility and good physical properties. The standard commodity grade of diammonium phosphate is 18-46-0. Pure and completely soluble ammonium phosphates are used mainly as liquid fertilizers. In Britain, diammonium phosphate is not sold directly in this form, but is used to make compound fertilizers with a wide variety of plant foods.

Возможный контакт

Used in fireproofing of textiles; wood and paper; in soldering flux; as a fertilizer; a buffer; in baking powder and food additives.

Перевозки

There are no DOT/UN listed requirements.

Методы очистки

Crystallise it from water (0.7mL/g) between 100o and 0o.

Несовместимости

Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong bases, strong acids, oxoacids, epoxides. Contact with air causes this chemical to produce anhydrous ammonia fumes.

Утилизация отходов

May be flushed to sewer with huge volumes of water.