Potassium permanganate KMnO4 it is a dark-purple crystals permanganates. Potassium permanganate is always sold in the drugstore as an antiseptic and antimicrobial agent (a very strong oxidant!). Many travelers take the potassium permanganate with you to prevent drinking water on the road (enough to dissolve a few crystals, as water significantly cleared).
Concentrated aqueous potassium permanganate is a very strong oxidant, it oxidizes organic compounds (plastic, wood, dyes). When heated crystals of potassium permanganate (200-250 C), it gradually turns into emerald dark-green crystals of potassium permanganate - this is the anhydrous salt potassium manganate K2MnO4. In this rapidly releases oxygen and forms manganese dioxide (one of the main ways to get oxygen in the laboratory).
Potassium permanganate fine "eats" into the metal and can seriously damage, for example, a metal sink, a bathroom and a T.T. In case of a spill of potassium permanganate remain dark brown spots, that are doesn't wash with standard ways. This is due to the decay of potassium permanganate for compounds, one of which is oxide of manganese, MnO2 - dark brown friable substance. Ruined sink with chemicals and to clean it will also chemically.
Getting potassium permanganate
Getting potassium permanganate in the industry with useing electrolysis of concentrated solution of potassium hydroxide with the manganese anode. In the process of electrolysis, the anode material gradually dissolves with the formation of the familiar purple of a solution containing permanganate ions. At the cathode is hydrogen evolution. Moderately soluble in water potassium permanganate stands out as sediment. It would be tempting instead of the usual potassium permanganate to produce a permanganate of sodium, because the sodium hydroxide more readily available than potassium hydroxide. However, in these cases, to allocate the sodium permanganate NaMnO4 is impossible: in contrast to potassium permanganate KMnO4, it is perfectly soluble in water (at 20 0C its solubility is 144 g per 100 g of water).
In neutral or weakly alkaline medium permanganate passes into the hydrated oxide of manganese:
In neutral or weakly alkaline medium permanganate ion (potassium permanganate) is reduced to manganese oxide (IV):
MnO4+2H2O+3e→ MnO2+4OH-. Especially manganese shows the oxidizing ability in acidic medium:
Strong acidified permanganate solution literally burns many organic compounds turning them into carbon dioxide and water. This is sometimes used by chemists for washing laboratory glassware, contaminated poorly washed off the remnants of organic substances.
Solid potassium permanganate and its solid solutions can be dangerous. If poisoning concentrated solution of potassium permanganate occurs burns of the mouth, esophagus and stomach. If You swallowed the solution, you should immediately wash out the stomach with warm water with addition of activated charcoal. To do this, you can also use a solution containing two liters of water half a cup of weak solution hydrogen peroxide (H2O2) and one glass of vinegar. In this case, the manganese ions are transferred into less harmful cations of manganese, and the chemical reaction proceeds as follows:
Hydrogen peroxide H2O2. Thickish, colorless liquid. Hydrogen peroxide is used in the same as potassium permanganate as antimicrobials. Hydrogen peroxide does not tolerate direct sunlight. In light the peroxide loses oxygen and quickly decomposes to water and singlet oxygen. Some additives, for example, a solid manganese dioxide MnO2, potassium permanganate decompos peroxide so rapidly that peroxide "boils".
An addition, the concentrated solution of hydrogen peroxide presence of manganese dioxide becomes explosive. The presence of the smallest particles of manganese dioxide can lead to instantaneous decomposition of the peroxide to form oxygen and water. The reaction proceeds as follows:
2H2O2→ 2H2O + O2
Hydrogen peroxide can be found in the drugstore in a 3%, 5%, 10% solutions, as well as the names of "peroxide" or "gidroperit" in the form of white tablets. Also used a concentrated solution (30%) of hydrogen peroxide, called "perhydrol". Perhydrol is used in medical clinics. At home, you can use the peroxide solution in the economic order - for example, for removing stains on fabrics. But we must not forget that the strongest oxidant. On the skin a concentrated solution of peroxide (perhydrol) causes severe burns. Especially protect your eyes! When hydrogen peroxide contact with living tissues it decomposes to release oxygen. Diluted solutions of hydrogen peroxide is used as a styptic and disinfectant: blood enzyme breaks down peroxide into water and active oxygen, which reliably disinfects the wound. However, its effect is short-term, therefore, stopping the bleeding, it is necessary to treat the wound by all the rules and apply a bandage. Hydrogen peroxide helps to cope with infection in the oral cavity or throat, at the same time to get rid of smell.
Hydrogen peroxide together with a coloring agent widely used for hair dyeing.
Storing hydrogen peroxide should be in the bottle from dark glass and in a cool place.