The tellurate ion
An ion is an atom or molecule in which the total number of electrons is not equal to the total number of protons, giving it a net positive or negative electrical charge. The name was given by physicist Michael Faraday for the substances that allow a current to pass between electrodes in a...
Unlike sulfate, tellurate is a somewhat good oxidizer; it can be reduced to tellurite
The tellurite ion is TeO32−. A tellurite is a compound that contains this ion. An example is sodium tellurite. Tellurites are one of the more stable tellurium compounds, although they can be reduced to elemental tellurium by electrolysis or a strong reducing agent.-Acidified forms:In...
Tellurate exists in two forms, metatellurate
, and orthotellurate
Compounds include metatellurates
. Metatellurates are analogous to sulfate
In inorganic chemistry, a sulfate is a salt of sulfuric acid.-Chemical properties:...
s, but they are rare. Orthotellurates are much more common and this forms most of the chemistry of tellurates.
In neutral conditions, pentahydrogen orthotellurate
, is most common; in basic conditions, tetrahydrogen orthotellurate
, is found; in acid conditions, the orthotelluric acid
Telluric acid is a chemical compound with the formula Te6. It is a white solid made up of octahedral Te6 molecules which persist in aqueous solution...
, has a molecular weight of 191.60 g/mole. It belongs to the Td
molecular point group, thus it has a tetrahedral shape even though two of its oxygen atoms are double bonded.
- TeO42− → TeO32− + 1/2O2 (E0= −1.042 V)
or standard reduction potential value is significant as it gives an indication of the strength of the tellurate ion as an oxidizing agent.
, has a molecular weight of 223.6 g/mole. It belongs to the Oh
molecular point group, thus it has an octahedral shape.
has two NMR active nuclei, 123
Te and 125
Te has an abundance of 0.9% and a nuclear spin (I) of 1/2. 125
Te has an abundance of 7% and an equivalent nuclear spin. 125
Te is more commonly performed because it has a higher sensitivity. The metatellurate
anion has a chemical shift
In nuclear magnetic resonance spectroscopy, the chemical shift is the resonant frequency of a nucleus relative to a standard. Often the position and number of chemical shifts are diagnostic of the structure of a molecule...
around 610 ppm when analyzed using 125
Te NMR at 25°C at a frequency of 94.735 MHz and referenced externally against aqueous 1.0 M telluric acid.
List of some known salts involving metatellurate anions