Question

How does phosphorus react with water?

Answer 1

Phosphorus is a fascinating element that occurs in at least three very different forms. If left exposed to the air, it catches fire on its own.

White phosphorus is poisonous and can spontaneously ignite when it comes in contact with air. For this reason, white phosphorus must be stored under water.
Phosphorous be stored under water without any observable reaction.

Phophorous can be stored under water, but when finely divided it decomposes water producing hydrogen phosphide. When boiled with water, phosphine and hypophosphorous acid are produced.

2 P + 3 H2O --> PH3 + H3PO3

Explaining the Lack of Observable Reactivity :

So why is there no obvious reaction when bulk white phoshorous is placed in water? There are several possible explanations. There could be a coat of something forming on the surface that prevents further reaction. For example, trying to dissolve large pieces of phosphorous pentoxide in water can be difficult if it has not been finely divided before. It has a tendency to form a protective viscous coating that inhibits further hydrolysis. In the case of elemental phosphorous reacting with water, it might be analogous to trying to hydrate silica. Si(OH)4 is quite stable, either as a solid or in aqueous solution, but it is essentially impossible to make bulk solid SiO2 react with water. Another possible reason could be activitation energy, although this seems less likely.