Tellurous acid explained

Tellurous acid is an inorganic compound with the formula H₂TeO₃. It is the oxoacid of tellurium(IV). This compound is not well characterized. An alternative way of writing its formula is (HO)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.

Properties

In contrast to the analogous compound selenous acid, tellurous acid is only metastable. Most tellurite salts contain the ion. Oxidation of its aqueous solution with hydrogen peroxide gives the tellurate ion. It is usually prepared as an aqueous solution where it acts as a weak acid.^{[1] [2]}

H₂TeO₃ + H₂O H₃O⁺ + K_a1 =

+ H₂O H₃O⁺ + K_a2 =

Notes and References

1. Book: Inorganic Chemistry . 3rd. Chapter 16: The group 16 elements. Catherine E. Housecroft. Alan G. Sharpe. Pearson. 2008. 978-0-13-175553-6. 524.
2. Web site: Ionization Constants for Weak Acids . www.austincc.edu . dead . https://web.archive.org/web/20141020041236/http://www.austincc.edu/chemlab/weakacid . 2014-10-20.