What is PI3? Important knowledge about PI3.

1. Definition of PI₃

Phosphorus triiodide, also known as PI₃, is a chemical compound of Phosphorus and Iodine. A PI₃ molecule consists of one Phosphorus atom connected to three Iodine atoms. The atomic weight of PI₃ is 411.69 g/mol. In a PI₃ molecule, the Phosphorus atom is at the center, with the three Iodine atoms surrounding it to form a triangle. PI₃ does not form ions but exists in the form of a central molecule.

2. Properties: PI₃

PI₃ is a brownish-red solid that is odorless and neither acidic nor basic. PI₃ burns easily in air to form I₂ and P₂O₅. It can also react with water to form I₂ and phosphoric acid.

3. Common chemical equations involving PI₃

PI₃ can react with metals like Sb, Bi to form iodide and phosphide salts. For example: PI₃ + 3Sb -> 3SbI₃ + P. When reacting with acid, PI₃ will form I₂ and phosphoric acid. For example: PI₃ + 6HNO₃ -> 3HI + H₃PO₄ + 3NO₂ + H₂O. PI₃ can also react with non-metals like O₂, S to form oxides and sulfides. For example: PI₃ + O₂ -> P₂O₅ + 3I₂. Finally, PI₃ can also react with salts like NaI to form Na₃PO₄ and I₂.

4. Synthesis of PI₃

PI₃ can be synthesized in the lab by reacting P with I₂. For example: P + 3I₂ -> 2PI₃. PI₃ can also be industrially synthesized through the thermal decomposition of PI₅.