Potassium hypomanganate is the
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 chemist ...
with the formula . Also known as potassium manganate(V), this bright blue solid is a rare example of a salt with the
hypomanganate
In chemistry, hypomanganate, also called manganate(V) or tetraoxidomanganate(3−), is a trivalent anion ( negative ion) composed of manganese and oxygen, with formula .
Hypomanganates are usually bright blue.D. Reinen, W. Rauw, U. Kesper, M. A ...
or manganate(V) anion, where the
manganese
Manganese is a chemical element with the symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese is a transition metal with a multifaceted array of industrial alloy use ...
atom is in the +5
oxidation
Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a d ...
state.
Preparative routes
*by two-electron
reduction of
potassium permanganate
Potassium permanganate is an inorganic compound with the chemical formula KMnO4. It is a purplish-black crystalline salt, that dissolves in water as K+ and , an intensely pink to purple solution.
Potassium permanganate is widely used in the c ...
with excess
potassium sulfite
Potassium sulfite is the inorganic compound with the formula K2SO3. It is the salt of potassium cation and sulfite anion. It is a white solid that is highly soluble in water.
Use
Potassium sulfite is widely used for preserving food and bever ...
;
[.][.]
:
*by the single-electron reduction of
potassium manganate
Potassium manganate is the inorganic compound with the formula . This green-colored salt is an intermediate in the industrial synthesis of potassium permanganate (), a common chemical. Occasionally, potassium manganate and potassium ''per''manga ...
with
hydrogen peroxide
Hydrogen peroxide is a chemical compound with the formula . In its pure form, it is a very pale blue liquid that is slightly more viscous than water. It is used as an oxidizer, bleaching agent, and antiseptic, usually as a dilute solution (3%†...
in 10 M
potassium hydroxide
Potassium hydroxide is an inorganic compound with the formula K OH, and is commonly called caustic potash.
Along with sodium hydroxide (NaOH), KOH is a prototypical strong base. It has many industrial and niche applications, most of which exp ...
solution;
[.]
:
*by the single-electron reduction of potassium manganate with
mandelate
Mandelic acid is an aromatic alpha hydroxy acid with the molecular formula C6H5CH(OH)CO2H. It is a white crystalline solid that is soluble in water and polar organic solvents. It is a useful precursor to various drugs. The molecule is chiral. Th ...
in 3–10 M potassium hydroxide solution;
:
*by
disproportionation
In chemistry, disproportionation, sometimes called dismutation, is a redox reaction in which one compound of intermediate oxidation state converts to two compounds, one of higher and one of lower oxidation states. More generally, the term can b ...
when
manganese dioxide
Manganese dioxide is the inorganic compound with the formula . This blackish or brown solid occurs naturally as the mineral pyrolusite, which is the main ore of manganese and a component of manganese nodules. The principal use for is for dry-cell ...
is dissolved in a concentrated solution of potassium hydroxide;
:
The compound is unstable due to the tendency of the hypomanganate anion to disproportionate in all but the most alkaline solutions.
References
{{manganese compounds
Potassium compounds
Manganese(V) compounds