Potassium dihydrogen phosphate, with the chemical formula KH₂PO₄, is an inorganic compound, commonly found as a colorless or white crystalline powder.
Basic properties：
- Appearance: Colorless or white crystalline powder, easily soluble in water, the aqueous solution is weakly acidic.
- Solubility: easily soluble in water, insoluble in ethanol.
- pH value: The pH of 1% aqueous solution is about 4.5.
Main Application：
- Agriculture: As a high-efficiency phosphorus-potassium compound fertilizer, it is used to promote crop growth and increase yield.
- Food industry: As an acidity regulator, buffer, nutritional supplement, etc., used in beverages, dairy products, etc.
- Medical field: used as a buffer and electrolyte supplement.
- Laboratory: Common reagents for buffer solution preparation and chemical analysis.
- Others: Also used in textile, papermaking, detergent and other industries.
Preparation method：
It is mainly produced by the reaction of phosphoric acid with potassium hydroxide or potassium carbonate. The reaction is as follows:
- H₃PO₄ + KOH → KH₂PO₄ + H₂O
- H₃PO₄ + 0.5K₂CO₃ → KH₂PO₄ + 0.5CO₂ + 0.5H₂O
Safety precautions：
- Inhalation: May irritate the respiratory tract, so please operate in a well-ventilated place.
- Contact: May irritate the skin and eyes, so please wear protective equipment when operating.
- Ingestion: Ingestion of large amounts may cause gastrointestinal discomfort, so please avoid accidental ingestion.
Storage：
It should be stored in a cool, dry, ventilated place, away from alkalis and flammable materials.
Summary：
Potassium dihydrogen phosphate is widely used in agriculture, food, medicine and other fields. When using it, attention should be paid to safe operation and storage conditions.