Tellurous acid
Tellurous acid is an inorganic compound with the formula H2TeO3. It is the oxoacid of tellurium. This compound is not well characterized. An alternative way of writing its formula is 2TeO. In principle, tellurous acid would form by treatment of tellurium dioxide with water, that is by hydrolysis. The related conjugate base is well known in the form of several salts such as potassium hydrogen tellurite, KHTeO3.