Manganese – solid gray metal. In connections he can show oxidation levels +2, +4, +6 and +7. In KMnO4 potassium permanganate it is in the maximum oxidation level +7. Other names of this substance – potassium salt of manganic acid, margantsovokisly potassium, in Latin – kalii permanganas.
As potassium permanganate looks
Permanganate of potassium represents dark-violet, almost black crystals. At dissolution in water, depending on concentration, it gives solution from light pink to a saturated violet shade. In KMnO4 hot water it is dissolved better. Crystals of substance or strongly concentrated solution at hit on skin or mucous can cause burns.
Chemical properties of permanganate of potassium
Potassium permanganate – oxygen-containing potassium salt. As to K cation (+) there corresponds the strong basis of KOH, and to MnO4 anion (-) – strong manganic HMnO4 acid, KMnO4 salt is not hydrolyzed.
KMnO4 is the strongest oxidizer. It easily oxidizes many inorganic and organic matter. Products of restoration of permanganate of potassium depend on conditions in which reaction proceeds. So, in acidic environment it is restored to Mn(2+), in neutral – to MnO2, in alkaline – to MnO4(2-). For example, if to add K2SO3 potassium sulfite to the acidified violet solution of permanganate of potassium, it will become colourless as Mn (II) salt is formed: 2KMnO4+5K2SO3+3H2SO4=2MnSO4+6K2SO4+3H2O.Eto high-quality reaction to MnO4 ion (-).
How to distinguish oxide of MnO2 manganese (IV)
Oxide of MnO2 manganese (IV) – one of the most important compounds of this metal. It is the brown-black oxide insoluble in water, the main component of manganous peroxide. As well as KMnO4, MnO2 is strong oxidizer that is used, for example, when receiving chlorine: MnO2+4HCl=MnCl2+Cl2 +2N2O.Buryy the deposit of MnO2 drops out at effect of sulfite of K2SO3 potassium on neutral solution of permanganate. Manganese oxidation level at the same time changes from +7 to +4:2KMnO4+3K2SO3+H2O=2MnO2 ↓+3K2SO4+2KOH.
Restoration of permanganate to the manganat in the alkaline environment
In strongly alkaline environment, at high concentration of alkali, permanganate of potassium is restored by potassium sulfite to the K2MnO4:2KMnO4+K2SO3+2KOH=2K2MnO4+K2SO4+H2O.Fioletovaya manganat the solution coloring at the same time changes on green. Manganat of potassium – the compound of manganese steady in the alkaline environment.
Use of permanganate of potassium
Permanganate of potassium finds broad application as oxidizer in chemical laboratories and the industry. 0.1% solution are used in medicine and in life for disinfection, rinsings, treatment of burns, removal of toxins.