Properties: Dipotassium hydrogen phosphate trihydrate is white crystal with water. Anhydrous is white powder. Easily soluble in water, the aqueous solution is slightly alkaline, slightly soluble in alcohol, hygroscopic, and self-dissolving at high temperature. Anhydrous dipotassium hydrogen phosphate is converted into potassium pyrophosphate when heated to 204°C.

Properties: Colorless transparent crystal, stable in air, soluble in water (22.6g/100ml), insoluble in ethanol, deliquescence. When heated to 400 ℃, it melts into a transparent liquid, and after cooling, it solidifies into an opaque glassy potassium metaphosphate.

Properties: White powder or block, the apparent specific gravity is above 0.3, the melting point is 1100 ° C, soluble in water, insoluble in alcohol, the aqueous solution is alkaline. It has high solubility in water (187 grams per 100 grams of water at 25°C), and has a slight deliquescence.

Properties: White granular crystal, relative density 1.619, melting point 155℃, easily soluble in water, insoluble in alcohol, PH value of 1% aqueous solution is 8.0, gradually loses ammonia in the air to form ammonium dihydrogen phosphate.

Properties: White granular crystal, relative density 1.803, melting point 190℃, easily soluble in water, slightly soluble in alcohol, insoluble in ketone, PH value of 1% aqueous solution is 4.5.

Properties: colorless transparent viscous liquid or orthorhombic crystal, odorless, very sour taste, melting point 42.35 ℃, heated to 300 ℃ to become metaphosphoric acid, relative density 1.834, easily soluble in water, soluble in ethanol, can stimulate the skin Causes inflammation, destroys body tissue, erodes when heated in porcelain, and is hygroscopic.

Properties: white powder or white granules, relative density 1.86, soluble in water, insoluble in ethanol, hydrolyzed into phosphoric acid when the aqueous solution is heated with dilute mineral acid, hygroscopic, and forms six crystalline hydrates after absorbing water, when heated to above 220 ℃ Decompose into sodium metaphosphate.

Properties: White powder or fine particles, easily soluble in water, and its aqueous solution is alkaline.

Properties: Appearance is white or colorless granular crystals, easily weathered, soluble in water, insoluble in organic solvents, the aqueous solution is alkaline reaction, the pH value of 1% aqueous solution is 12.1, the relative density is 1.62, the melting point is 73.4 ° C, the dodecahydrate is heated When heated to 55~65℃, it becomes decahydrate; when heated to 65~100℃, it becomes hexahydrate; when heated to 100~213℃, it becomes hemihydrate; when heated to above 212℃, it becomes anhydrous.

Properties: Dodecahydrate is a white crystal with a relative density of 1.52, easy to weather, melts at 35°C and loses 5 crystal waters, becomes anhydrous at 100°C, and sodium pyrophosphate at 250°C; anhydrous is white Powder, easy to deliquescence; both are easily soluble in water, the aqueous solution is weakly alkaline, insoluble in alcohol.

Properties: Anhydrous sodium dihydrogen phosphate is a white powder with a melting point of 190°C. The dihydrate is a white granular crystal with a relative density of 1.915 and a melting point of 57.40°C; both are easily soluble in water, insoluble in organic solvents, and absorb moisture in the air.

Properties: white powder, easily soluble in water, insoluble in alcohol, relative density 2.45, melting point 890 ℃, the aqueous solution is weakly alkaline, easy to deliquescence in the air, the aqueous solution is relatively stable at 70 ℃, hydrolyzed into disodium hydrogen phosphate when boiled .