The chemical formula for thiosulfate is Na2S2O3 when in its sodium salt form, or simply S2O3^2- for the thiosulfate ion. This compound is typically found in a hydrated form, such as sodium thiosulfate pentahydrate (Na2S2O3ยท5H2O).
In terms of its chemical nature, sodium thiosulfate is considered an ionic compound. It consists of sodium ions (Na+) and thiosulfate ions (S2O32-). The bond formed between sodium ions and thiosulfate ions is ionic due to the transfer of electrons from sodium, a metal, to the thiosulfate ion, which is a polyatomic anion. Ionic compounds typically have high melting and boiling points and are soluble in water, which is consistent with the properties of sodium thiosulfate.
In summary, sodium thiosulfate has the formula Na2S2O3, and it is classified as an ionic compound.