Potassium dihydrogen phosphate is a chemical with the chemical formula KH2PO4. Deliquescent. When heated to 400 ℃, it melts into a transparent liquid and solidifies into opaque glassy potassium metaphosphate after cooling. It is stable in air, soluble in water and insoluble in ethanol. Used as buffer and culture agent in industry; It is also used as bacterial culture agent, seasoning agent for the synthesis of sake, raw material for the preparation of potassium metaphosphate, culture agent, fortifier, bulking agent and fermentation assistant for brewing yeast. It is used as high-efficiency phosphorus and potassium compound fertilizer in agriculture.