Let us know about the Manganese Oxide. Manganese oxide (MnO 2 ) is an inorganic chemical compound formed by the element manganese with an oxidation number of +4 and oxygen, which has an oxidation number of -2 in the formation of the oxide. It is also known as manganese(IV) oxide and manganese anhydride.
This is a solid to dark black coffee. This mineral occurs in nature as pyrolusite, black and crystallized with dendrites (branched elongation). It can be obtained as a black residue in the reaction between ethylene and potassium permanganate after the formation of glycol by the oxidation action of potassium permanganate. It is of great importance in the glass industry due to its character as an oxidizing agent, as it removes the green color from ferrous compounds and converts them to iron.
chemical composition
The chemical composition of the compound corresponds to that of an anhydride and not a basic oxide, as would be expected since it consists of a metal and a non-metal.
This particular case is due to the behavior assumed by manganese in different oxidation states. Thus, the oxidation of +2 and +3 forms the oxides MnO and Mn 2 O 3 respectively, when reacted with water, they form manganese hydroxide and manganese hydroxide, respectively.
However, M.N. 2 O 3 In a slightly acidic medium it behaves as an anhydride. With oxidation of +4, +6 and +7, MnO 2 , MnO 3 and MnO 4 react with water to form acids.
In a slightly acidic medium MnO 2 It behaves like a basic oxide, so it can form the corresponding hydroxide.
It should be borne in mind that in this case the amphoteric properties are not mentioned, according to which a compound can behave as an acid or as a base. This is a special case of Mn behavior.
Applications
It is used as a source of manganese
– As an oxidant in alkaline batteries
– Paints for glass, ceramic and porcelain.
– In obtaining chlorine and iodine.
– In the decomposition of hydrogen peroxide to form gaseous oxygen and water.
– In the decomposition reaction of potassium chlorate to produce gaseous oxygen and potassium chloride.
– oxidizes primary alcohols to aldehydes and secondary ketones by dissolving in acetone or in dichloromethane.
– Manufacture of alkaline batteries.
as a catalyst
It is applied to oxide-reduction reactions, to remove sulfides such as H 2 S and cations such as Fe +2 and Mn . +2 , Arsenic and radioactive substances found in groundwater that are contaminated by such compounds.
This contamination can result from either the uncontrolled dumping of toxins, washing away of contaminated soil or the presence of chemical elements at the time of water extraction.
MnO 2 is the most effective means for removing this class of impurities from high purity groundwater obtained from pyrolusite used as a filter (Filox).
health effects
– Avoid contact with skin.
– In case of contact, wash the area concerned.
Do not inhale the powder.
Irritation and redness may be observed on contact with eyes. Wash off with plenty of water, let the water run through the eyes and call for medical help in severe cases.
Burning and redness are observed on contact with the skin. Wash the affected area with plenty of water and soap. Prolonged skin contact strips away your natural fat, leading to a dermatitis.
– Inhalation can cause flu-like condition (metallic fumes). The condition is characterized by high fever, chills, pain in the mouth and throat, muscle pain and headache.
It can irritate the respiratory system and increase the incidence of respiratory infections (pneumonia). Absorption of inorganic manganese salts through the lungs is unlikely to cause intoxication, but can lead to chronic toxicity.
– Chronic exposure to dust or smoke from manganese dioxide over a long period of time can affect the central nervous system and lead to Parkinson’s disease, difficulty walking, muscle spasms and behavior changes.
– May cause abdominal pain and nausea.
– It is not flammable, but it helps to spread fire to incandescent materials. If heated to a temperature above 535 ° C, the substance decomposes on manganese oxide (III) Mn 2 O 3 and oxygen, which is flammable and increases the risk of fire. In this case the fire should be extinguished with foam or carbon dioxide.
– In case of leakage, do not manipulate the premises without proper personal protection.
– Store the compound in tightly closed containers, in a cool and dry place and away from incompatible substances such as organic matter and combustible materials.
– The storage space should be dry and the floor should be resistant to acid corrosion and with good drainage.
– Personal protective equipment should be used, such as gloves, safety goggles, vapor-proof filter masks, dust and smoke.
