Calcium itself is not water-soluble, but many calcium compounds are. For instance, calcium chloride (CaCl2) dissolves readily in water, forming a clear solution. The solubility of calcium compounds varies, and some are only slightly soluble.
Here are a few examples of calcium compound solubility:
- Calcium carbonate (CaCO3): Has a solubility of 14 mg/L. This solubility increases by a factor of five in the presence of carbon dioxide.
- Calcium phosphate (Ca3(PO4)2): Has a solubility of 20 mg/L.
- Calcium fluoride (CaF2): Has a solubility of 16 mg/L.
It's important to note that the term "water-soluble calcium" often refers to calcium supplements designed for easy absorption by the body. These supplements typically contain calcium in a form that readily dissolves in water, making them easier to ingest.
In summary, while elemental calcium is not soluble in water, many calcium compounds are, making them available for various applications and biological processes.
