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Hydrogen peroxide is a chemical compound with the formula H 2 O 2.In its pure form, it is a very pale blue [5] liquid that is slightly more viscous than water.It is used as an oxidizer, bleaching agent, and antiseptic, usually as a dilute solution (3%–6% by weight) in water for consumer use and in higher concentrations for industrial use.
About 50 ml of concentrated (>12%) [5] hydrogen peroxide is first mixed with liquid soap or dishwashing detergent. Then, a catalyst, often around 10 ml potassium iodide solution or catalase from baker's yeast, is added to make the hydrogen peroxide decompose very quickly. Hydrogen peroxide breaks down into oxygen and water.
The hydrogen peroxide needs to be at least 12% w/w concentration, as lower concentrations lead to poor yields. Citric acid is overall superior to other acids, providing a yield of up to about 50%. The molecule adopts a cage-like structure with the nitrogen atoms having an unusual trigonal planar geometry. [3]
Acetone peroxide (specifically, triacetone triperoxide) was discovered in 1895 by the German chemist Richard Wolffenstein. [5] [6] [7] Wolffenstein combined acetone and hydrogen peroxide, and then he allowed the mixture to stand for a week at room temperature, during which time a small quantity of crystals precipitated, which had a melting point of 97 °C (207 °F).
Retrobright (stylized as retr0bright or Retrobrite [1]) is a hydrogen peroxide-based process for removing yellowing from ABS plastics. Yellowing in ABS plastic occurs when it is exposed to UV light or excessive heat, which causes photo-oxidation of polymers that breaks polymer chains and causes the plastic to yellow and become brittle. [2]
It is an oxidising agent roughly equivalent to hydrogen peroxide, and much stronger than molecular oxygen. Nitrous oxide is not flammable at low pressure/temperature, but at about 300 °C (572 °F), its breakdown delivers more oxygen than atmospheric air.
A 12% solution is widely used in waterworks for the chlorination of water, and a 15% solution is more commonly [39] used for disinfection of wastewater in treatment plants. Sodium hypochlorite can also be used for point-of-use disinfection of drinking water, [ 40 ] taking 0.2–2 mg of sodium hypochlorite per liter of water.
It is often used in conjunction with oxygen and hydrogen peroxide to eliminate the need for chlorine-containing compounds in the manufacture of high-quality, white paper. [156] Ozone can be used to detoxify cyanide wastes (for example from gold and silver mining) by oxidizing cyanide to cyanate and eventually to carbon dioxide. [157]