Chemical formula: H3PO4
Chemical name: Phosphoric Acid; H3PO4
Origin: Vietnam, Korea, China
Specification: 35kg/can

Physical properties:
Phosphoric acid is a colorless crystalline solid, density 1.87 g/cm3; melting point = 42.350C (form H3PO4.H2O has melting point = 29.320C); decomposes at 2130C. Soluble in ethanol, water (in any ratio). In the crystal structure of H3PO4, there are tetrahedral PO4 groups. Linked together by hydrogen bonds. That structure is still retained in concentrated solutions of the acid in water and makes the solution viscous like sugar water.

The solubility of phosphoric acid in water is explained by the formation of hydrogen bonds between H3PO4 molecules and H2O molecules.

Chemical properties:
In the phosphoric acid molecule, P is at the +5 oxidation level, so phosphoric acid is difficult to reduce and does not have oxidizing properties like nitric acid. When heated gradually to 260oC, phosphoric acid loses water and turns into diphosphoric acid (H4P2O7); at 3000C, it turns into metaphosphoric acid (HPO3). Phosphoric acid is a triphasic acid with average strength. The acid constant at 250C has the values K1 = 7.10−3, K2 = 8.10−6, K3 = 4.10−13. Phosphoric acid solution has the common properties of acids such as turning litmus red. Reacts with basic oxides, bases, salts, metals. When reacting with basic oxides or bases. Depending on the amount of reactant, the product is a neutral salt, an acid salt, or a mixture of salts.

Preparation
In industry, H3PO4 is prepared by extraction method (decomposing phosphorite or apatite ore with concentrated sulfuric acid. However, this method produces impure phosphoric acid of low quality). To obtain H3PO4 with higher purity and concentration, it is prepared by thermal method. Reduce phosphorite ore, apatite to P, oxidize P to P2O5, absorb with water