While selenic acid has the formula H2SeO4 and thus is directly related to sulfuric acid, telluric acid is best visualized as H6TeO6 or Te(OH)6.
a. What is the oxidation state of tellurium in Te(OH)6?
b. Despite its structural differences with sulfuric and selenic acid, telluric acid is a diprotic acid with pKa1 = 7.68 and pKa2 = 11.29. Telluric acid can be prepared by hydrolysis of tellurium hexafluoride according to the equation
TeF6(g) + 6H2O(l) → Te(OH)6(aq) + 6HF(aq)
Tellurium hexafluoride can be prepared by the reaction of elemental tellurium with fluorine gas: