Tellurous acid is an
inorganic compound
In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as '' inorganic chemi ...
with the
formula H
2TeO
3. It is the
oxoacid
An oxyacid, oxoacid, or ternary acid is an acid that contains oxygen. Specifically, it is a compound that contains hydrogen, oxygen, and at least one other element, with at least one hydrogen atom bonded to oxygen that can dissociate to produce ...
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
Tellurium dioxide (TeO2) is a solid oxide of tellurium. It is encountered in two different forms, the yellow orthorhombic mineral tellurite, β-TeO2, and the synthetic, colourless tetragonal (paratellurite), α-TeO2. Most of the information regar ...
with water, that is by hydrolysis. The related conjugate base is well known in the form of several salts such as potassium hydrogen tellurite, KHTeO
3.
Properties
In contrast to the analogous compound
selenous acid
Selenous acid (or selenious acid) is the chemical compound with the formula . Structurally, it is more accurately described by . It is the principal oxoacid of selenium; the other being selenic acid.
Formation and properties
Selenous acid is ...
, 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.
[ ]
:H
2TeO
3 + H
2O H
3O
+ + ''K''
a1 =
: + H
2O H
3O
+ + ''K''
a2 =
References
Hydrogen compounds
Tellurites
Oxoacids
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