Calcium hydrogen phosphate, also known as dicalcium phosphate, has limited solubility in water at ambient temperatures.The solubility of calcium hydrogen phosphate depends on the specific phase of the compound, as there are different forms with varying solubility characteristics.

Dicalcium Phosphate Dihydrate (DCPD):

This is the most common form with the chemical formula CaHPO4 · 2H2O.

Solubility in water: Dicalcium phosphate dihydrate has a very low solubility in water, and it is practically insoluble at room temperature.The solubility increases with temperature but remains relatively low.

Dicalcium Phosphate Anhydrous (DCPA):

The anhydrous form of dicalcium phosphate has the chemical formula CaHPO4.

Solubility in water: Anhydrous dicalcium phosphate also has limited solubility in water.Like the dihydrate form, it is practically insoluble at room temperature and shows increased solubility with higher temperatures.

The low solubility of calcium hydrogen phosphate in water is attributed to its ionic nature and the strong electrostatic forces that hold the calcium and phosphate ions together in the crystal lattice.As a result, calcium hydrogen phosphate is often used as an ingredient in various products, such as supplements, where slow and controlled release of calcium and phosphate ions is desirable.

The solubility of calcium hydrogen phosphate can be influenced by factors such as pH, temperature, and the presence of other ions or compounds.In acidic conditions, the solubility may slightly increase compared to neutral or basic conditions.