CaSO2HO

CaSO2HO is not a standard or unambiguous chemical formula in conventional nomenclature. In various sources it has appeared as an informal or miswritten notation that could refer to different calcium sulfite–related species. Because the formula lacks a clear specification of hydration state and anionic identity, its exact meaning is ambiguous without context.

One possible interpretation is calcium bisulfite, Ca(HSO3)2, a salt formed from calcium ions and bisulfite anions. In solution, bisulfite acts as a reducing agent and can participate in reactions related to sulfur dioxide chemistry. As a solid, calcium bisulfite may be less common than other calcium sulfite salts and can decompose upon heating or aging, releasing sulfur dioxide.

Another possible interpretation is a hydrated calcium sulfite species, such as calcium sulfite monohydrate, CaSO3·H2O. This form can arise in flue-gas desulfurization byproducts or in aqueous systems where sulfite solutions interact with calcium compounds. Hydrated forms differ in solubility, stability, and tendency to oxidize to calcium sulfate (gypsum) over time.

Because CaSO2HO is not a precisely defined compound, any practical use or property claim should be tied to a clearly specified formula (for example, Ca(HSO3)2 or CaSO3·H2O) and tested conditions. In safety terms, sulfite and bisulfite salts can irritate skin and eyes and may release sulfur dioxide under certain conditions.

See also: calcium sulfite, calcium bisulfite, calcium sulfate hydrates.