Product Appearance
The appearance is a colorless viscous liquid, which forms crystals upon long standing, appearing as a colorless glassy solid. The pyrophosphate ion has strong coordination properties and is commonly used as an analytical reagent, such as a masking agent, and for the preparation of organic phosphate esters.
It can also be used in the copper electroplating process to adjust the pH value of the electroplating solution, as well as in other electroplating applications. It can also be used as a catalyst, in metal refining, and as a stabilizer for organic peroxides.
Basic Product Information | Chinese Name: | 焦磷酸 (Alias: 皮萨草) | Density: | 2.04g/cm3(25℃) | | English Name: | Pyrophosphoric acid | Appearance: | Colorless liquid | | Chemical Formula: | H4P2O7 | Molar Refractivity: | 23.68 | | Molecular Weight: | 177.98 | Molar Volume (m3/mol): | 732.2 | | CAS# | 2466-09-3 | Parachor (90.2K): | 262.9 | | Melting Point: | 61℃ | Safety Description: | S26 S36 S36/S37/S39 | | Solubility: | Soluble in water | Hazard Symbols: | Corrosive |
Properties and Stability
The pyrophosphate ion reacts with silver salts to form a white silver pyrophosphate precipitate. Pyrophosphoric acid is formed by heating orthophosphoric acid to 210℃, resulting in dehydration. It is soluble in ethanol. It is corrosive and can cause burns. Solid crystalline pyrophosphoric acid is highly hygroscopic and soluble in water and ethanol. When heated above its melting point, it decomposes into a liquid acid containing orthophosphoric acid, pyrophosphoric acid, trimetaphosphoric acid, polymetaphosphoric acid, etc. Crystalline pyrophosphoric acid does not decompose easily in ice water, but decomposes at high temperatures, increasing the amount of orthophosphoric acid. The general solid crystal is Type I pyrophosphoric acid (melting point 54.3℃). Type I crystals, when heated in a sealed tube at about 50℃ for several hours, transform into Type II pyrophosphoric acid (melting point 71.5℃), which is stable at room temperature. |
