H2TeO3

H2TeO3, commonly known as tellurous acid, is a hypothetical inorganic compound. While often written with this formula, it is not typically isolated as a discrete molecular species. Instead, it is believed to exist in aqueous solutions as hydrated forms of tellurium dioxide, TeO2. These hydrated forms are more accurately described as tellurium(IV) oxide hydrates or possibly as various polymeric species. The actual structure in solution is complex and depends on factors like concentration and pH.

Tellurous acid is a weak acid. In solution, it can react with bases to form tellurite salts. For example, reaction with sodium hydroxide would yield sodium tellurite, Na2TeO3. These tellurite salts contain the tellurite anion, [TeO3]2-, or related species. The chemistry of tellurous acid and its derivatives is relevant in areas such as analytical chemistry and the study of tellurium speciation in various environments. Research into its properties often focuses on its behavior in solution rather than the isolation of a pure H2TeO3 compound.