Dithionic acid
Encyclopedia
Dithionic acid, H2S2O6, is a chemical compound known only in solution
.
s have been discovered. All dithionates are readily soluble in water
. They are mild oxidizing and mild reducing agents. The structure of dithionate ion is like ethane
, but two SO3 groups adopt an almost eclipsed conformation. The S—S length is 2.15 Å; S—O bonds are rather short with bond length of 1.43 Å.
a sulfite
(from the +4 to the +5 oxidation state
), but on a larger scale they are made by oxidizing a cooled aqueous solution of sulfur dioxide
with MnO2:
The manganese dithionate solution formed can then be converted to dithionate salts of other metals by metathesis reactions:
Concentrated solutions of dithionic acid can subsequently be obtained treating a barium dithionate solution with sulfuric acid:
Solution
In chemistry, a solution is a homogeneous mixture composed of only one phase. In such a mixture, a solute is dissolved in another substance, known as a solvent. The solvent does the dissolving.- Types of solutions :...
.
Salts
Dithionic acid is dibasic and salts called dithionates are known. No acid saltAcid salt
Acid salt is a somewhat obscure term for a class of salts formed by the partial neutralization of diprotic or polyprotic acids. Because the parent acid is only partially neutralized, one or more replaceable hydrogen atoms remain. Typical acid salts have one or more alkali metal ions as well as one...
s have been discovered. All dithionates are readily soluble in water
Water
Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...
. They are mild oxidizing and mild reducing agents. The structure of dithionate ion is like ethane
Ethane
Ethane is a chemical compound with chemical formula C2H6. It is the only two-carbon alkane that is an aliphatic hydrocarbon. At standard temperature and pressure, ethane is a colorless, odorless gas....
, but two SO3 groups adopt an almost eclipsed conformation. The S—S length is 2.15 Å; S—O bonds are rather short with bond length of 1.43 Å.
Synthesis
Dithionates can be made by oxidizingRedox
Redox reactions describe all chemical reactions in which atoms have their oxidation state changed....
a sulfite
Sulfite
Sulfites are compounds that contain the sulfite ion SO. The sulfite ion is the conjugate base of bisulfite. Although the acid itself is elusive, its salts are widely used.-Structure:...
(from the +4 to the +5 oxidation state
Oxidation state
In chemistry, the oxidation state is an indicator of the degree of oxidation of an atom in a chemical compound. The formal oxidation state is the hypothetical charge that an atom would have if all bonds to atoms of different elements were 100% ionic. Oxidation states are typically represented by...
), but on a larger scale they are made by oxidizing a cooled aqueous solution of sulfur dioxide
Sulfur dioxide
Sulfur dioxide is the chemical compound with the formula . It is released by volcanoes and in various industrial processes. Since coal and petroleum often contain sulfur compounds, their combustion generates sulfur dioxide unless the sulfur compounds are removed before burning the fuel...
with MnO2:
- 2MnO2 + 3SO2 → MnS2O6 + MnSO4
The manganese dithionate solution formed can then be converted to dithionate salts of other metals by metathesis reactions:
- Ba2+(aq) + MnS2O6(aq) + MnSO4(aq) → BaSO4(s)↓ + BaS2O6·2H2O(aq)
Concentrated solutions of dithionic acid can subsequently be obtained treating a barium dithionate solution with sulfuric acid:
- BaS2O6(aq) + H2SO4(aq) → H2S2O6(aq) + BaSO4(s)↓