Tetraoxophosphates(V) come in three forms, for instance, sodium dihydrogen tetraoxophosphate(V), NaH2PO4, sodium hydrogen teteraoxophosphate(V), NaHPO4, and sodium tetraoxophosphate(V), Na3PO4. Two important tetraoxophosphates(V) are ammonium and calcium tetraoxophosphates(V).
Below are some of the agricultural and industrial uses of tetraoxophosphates(V).
- The most important use of tetraoxophosphates(V) is in the manufacture of inorganic fertilizers. Fertilizers which contain essential plant nutrients are added to the soil to promote the healthy growth of plants. The three most important plant nutrients are nitrogen potassium and phosphorus and plants absorb the soluble salts of these elements. The supply of nutrients to plants must be sustained by the application of fertilizers. In Nigeria, the commonly used inorganic fertilizers contain nitrogen, phosphorus and potassium(NPK) in definite proportions.
Several phosphorus compounds are used as fertilizers or synthetic manure to replenish the level of phosphorus in the soil. Calcium tetraoxophosphate(V), in the form of bone ash or rock phosphate, is not very useful because it is insoluble. Instead, the compound is treated with 65% tetraoxosulphate(VI) acid to form a mixture of calcium dihydrogen tetraoxosulphate(VI). This mixture, known as superphosphate, is one of the most commonly used phosphorus fertilizer. A more effective fertilizer, known as triple phosphate, can be made by treating calcium tetraoxophosphate(V) with tetraoxophosphate(V) acid. Another commonly used fertilizer is ammonium tetraoxophosphate(V), which also contains nitrogen. Nitrogenous fertilizers include ammonium compounds and trioxonitrates(V) while potassium is often supplied as potassium tetraoxosulpahte(VI).
- Tetraoxophosphate(V) acid and its salts are used in processed foods and drinks and in the making of baking powder and self raising floor.
- The acid and its salts are also used in making enamels, matches and glazes for pottery; refining petroleum; for fireproofing textiles and timber; for rustproofing steel articles before painting; and also used as catalysts, water softeners and detergents.