He Manganese acid Or permanganic acid is a dibasic acid (H2MnO4), formed of manganese, analogous to sulfuric acid. It is found only in solution and in manganate salts.
- Systematic name : Dihydrogen (tetraoxydomanganate).
- Type of compound : Oxoacids (ternary combinations formed by hydrogen, a non-metal element and oxygen).
- Molecular formula : H2MnO4
- Molecular mass : 120.9515
Examples of reactions
MnO 3 + H 2 O = H 2 MnO 4
KMnO 4 + H 2 O 2 = KO 2 + H 2 MnO 4
Permanganic acid solutions (up to 20%) are purple liquids with an ozone smell. The crystal hydrate (HMnO4 · 2H2O) is a purple crystalline solid that decomposes above 20 degrees Celsius.
Permanganic acid is a very strong oxidant, although milder than its anhydride. It spontaneously decomposes, wrapping oxygen and precipitating manganese dioxide, which catalyzes the further decomposition of the acid.
By cooling the unstable concentrated solution of the acid near to the freezing point, it may be prepared and crystal hydrate. The sources vary depending on the nature of this compound: according to some sources, it is a hydronium salt of permanganic acid, according to others, it is a polyangganic acid complex.
Excessively concentrated solutions of this acid can spontaneously decompose with the evolution of ozone. This allows the preparation of ozone chemically by reacting the potassium permanganate with sulfuric acid of medium concentration (50-80%).
This reaction produces an excessively concentrated solution of permanganic acid, which decomposes rapidly, releasing the ozone.
Sulfuric acid with a concentration above 80% should not be used for this reaction as this may lead to the formation of extremely hazardous anhydride (manganese epoxide).
Permanganic acid can be prepared by dissolving manganese epoxide in water, or by reacting barium permanganate with sulfuric acid. An impure solution can also be prepared by dissolving the potassium permanganate in medium concentration sulfuric acid (50-80%).
Not much is known about the hazards of permanganic acid, but it must be treated with caution since it is a strong acid and also a very strong oxidizer. In addition, it can release ozone, which is toxic.
It is impractical to store this acid because of its instability. It should be used as soon as it is done. The hydrate can be stored as long as it is frozen (below the freezing point of the water).
Permanganic acid can be discharged into the soil as it causes the compound to decompose, oxidizing the soil and becoming manganese dioxide, which is safe and insoluble.
The univalent anionic group MnO 4 derived from permanganic acid all being strong oxidizing agents. They are salts containing the MnO4- anion, normally deep red violet and with strong oxidizing properties.
1- Potassium permanganate
Molecular formula: KMnO4
158.032 g / mol
It is the best known of all permanganates. Also known as Condy crystals, it is a highly oxidizing, odorless, water-soluble compound in many organic solvents, has purple crystals, and a sweet taste. (Definition of the McGraw-Hill Dictionary of Scientific and Technical Information, 4th ed).
Potassium permanganate is not combustible but it speeds up the ignition of the combustible material. If the combustible material is finely divided, the mixture may be explosive. When it comes into contact with liquid combustible materials it may cause spontaneous ignition. Contact with sulfuric acid may cause fire or explosion. It is used to make other chemicals and as a disinfectant.
Pharmacology and Biochemistry
Pharmacological Classification: MeSH
Indicators and reagents
They are substances used for the detection, identification and analysis of chemical, biological or pathological processes or conditions.
Indicators are substances that change in physical aspect, for example of color, when it approaches the point where it passes between acidity and alkalinity. Reagents are substances used for the detection or determination of another substance by chemical or microscopic means, in particular the analysis.
The types of reagents are precipitants, solvents, oxidizers, reducers, fluxes and colorimetric reagents. (Hackh's Chemical Dictionary, 5th edition, page 301, pg.499).
As bleaching agents, odorants and oxidizing / reducing agents.
They can be prepared by oxidizing manganese dioxide with potassium chlorate in potassium hydroxide solution, then completing the oxidation with chlorine or air and carbon dioxide.
Safety and Hazards
"You can intensify the fire."
-It is harmful if swallowed.
- Causes severe skin burns.
- May cause eye injury.
- May cause respiratory irritation.
- It is suspected to cause genetic defects.
- You have the suspicion that it can damage the fertility and the fetus.
- Causes damage to organs through prolonged or repeated exposure.
- It is very toxic to aquatic organisms, with long lasting harmful effects.
Danger to health
It can cause burns and brown spots on the skin. If swallowed it causes severe affectation of the gastrointestinal system. It can be fatal if consumed over 4 ounces.
It is not combustible but increases the combustion of other substances. Causes irritant or toxic fumes or vapors in the fire.
Fire behavior: May cause fire in contact with fuels causing containers to explode. May cause a high risk of fire and explosion on contact with combustible substances or reducing agents.
It decomposes on heating and produces toxic fumes and irritating fumes. The substance is a strong oxidant. Reacts with combustible and reducing materials which creates fire and explosion hazard. Reacts violently with powdered metals, which creates fire hazard.
First aid if in contact with potassium permanganate
If swallowed, induce vomiting and continue with a thorough gastric lavage
Inhaling requires fresh air and rest. Artificial respiration may be necessary. It is necessary to consult a doctor.
If on skin, rinse with plenty of water for at least 15 minutes and then remove contaminated clothing and rinse again. It is also important to consult a doctor.
If eye contact occurs, rinse with plenty of water for several minutes. Get medical attention.
2- Sodium permanganate
Molecular formula: MnNaO4
Molecular weight: 141,924 g / mol
Sodium permanganate is a purple crystalline solid. Not combustible but accelerates the burning of combustible material. It may ignite spontaneously in contact with liquid combustible materials. Contact with sulfuric acid may cause fires or explosions. Used in medicine, as a disinfectant, and for many other uses.
Use and manufacture
It is used in industry as an oxidizing and reducing agent. Also used for water treatment, for bleaching textiles
Sodium manganate dissolves in water and chlorine or ozone is introduced. The solution is concentrated and crystallized.
3- Calcium permanganate
Molecular formula: CaMn2O8
Molecular weight: 277,946 g / mol
Calcium permanganate is a purple crystalline solid. It is used as a disinfectant and deodorant, in water purification, and for many other uses.
The manganic ion resulting from this permanganate is astringent which helps to suppress inflammation.