Adipic acid (yi) is oxalic acid, the molecular formula is C2H2O4, and its common name is oxalic acid. Its physical characteristics are as follows:
Properties: Colorless transparent crystal or powder. Its crystal structure has two forms, namely α type (diamond) and β type (monoclinic). No smell, sour taste.
Melting point: α type: 189.5℃, β type: 182℃.
Boiling point: The boiling point of the molecular solid model is 150℃ (sublimation).
Relative density: 1.653 (dihydrate), 1.9 (anhydrous). α type: 1.900, β type: 1.895.
Refractive index: 1.540
Stability: 189.5℃ decomposition
Solubility: Soluble in ethanol. Soluble in water. Slightly soluble in ether. Insoluble in benzene and chloroform. The water solubility is 90g/L (20 degrees Celsius).
Other properties: oxalic acid began to sublimate at 100℃, quickly sublimated at 125℃, and sublimated in large quantities at 157℃ and began to decompose.