Phosphoric acid decomposition process
Phosphoric acid is also a chemical substance. The process of its decomposition is the key to chemical changes.

Phosphoric acid ($H_3PO_3 $) will decompose under a specific environment. When the temperature gradually rises, or other factors urge, the chemical bonds in the phosphorous acid molecule gradually shift.

First, the bond forces between hydrogen atoms, phosphorus atoms and oxygen atoms in the phosphorous acid molecule change. Among them, the $P-O-H $bond and the $P-H $bond are both key. Due to heat or other reasons, the stability of the $P-H $bond is slightly weaker, and it first appears active.

Part of the phosphoric acid molecule, the $P - H $bond is broken, and hydrogen ($H_2 $) escapes. The rest becomes other phosphorus-containing compounds. The common one is phosphoric acid ($H_3PO_4 $). After the $P - H $bond is broken, the combination of atoms is rearranged, and after oxidation, the valence of phosphorus changes and finally forms phosphoric acid. This change can be expressed as the following formula: $2H_3PO_3\ longrightarrow H_3PO_4 + H_2 + HPO_2 $.

Among them, hypophosphoric acid ($HPO_2 $) is also one of the decomposition products. However, hypophosphoric acid is not a long-term stable thing. In the current situation, it may decompose again or react with other things.

The decomposition of phosphoric acid depends not only on the temperature, but also on the existence of catalysts. The higher the temperature, the greater the kinetic energy of the molecule, and the easier the bond breaking; if there is a suitable catalyst, the activation energy of the reaction can be reduced, and the speed of decomposition can be promoted.

The decomposition process of phosphoric acid is actually the clutching of atoms in the molecule, the breaking of bonds, and through various changes, various products can be formed. This is the wonder of chemical changes, and it should be deeply studied by chemistry students.