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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.
A typical mixture is 3 parts of concentrated sulfuric acid and 1 part of 30 wt. % hydrogen peroxide solution; [1] other protocols may use a 4:1 or even 7:1 mixture. A closely related mixture, sometimes called "base piranha", is a 5:1:1 mixture of water, ammonia solution ( NH 4 OH , or NH 3 (aq) ), and 30% hydrogen peroxide.
Hydrogen peroxide works best as a propellant in extremely high concentrations (roughly over 70%). Although any concentration of peroxide will generate some hot gas (oxygen plus some steam), at concentrations above approximately 67%, the heat of decomposing hydrogen peroxide becomes large enough to completely vaporize all the liquid at standard pressure.
The first step (called SC-1, where SC stands for Standard Clean) is performed with a solution of (ratios may vary) [2] 5 parts of deionized water; 1 part of ammonia water, (29% by weight of NH 3) 1 part of aqueous H 2 O 2 (hydrogen peroxide, 30%) at 75 or 80 °C [1] typically for 10 minutes. This base-peroxide mixture removes organic residues.
Elephant's toothpaste is a foamy substance caused by the quick decomposition of hydrogen peroxide (H 2 O 2) using potassium iodide (KI) or yeast and warm water as a catalyst. [1] How rapidly the reaction proceeds will depend on the concentration of hydrogen peroxide. [2] [3] [4]
The peracetic acid is a more effective bleaching agent than hydrogen peroxide itself. [ 4 ] [ 5 ] PAA is also formed naturally in the environment through a series of photochemical reactions involving formaldehyde and photo-oxidant radicals .
The peroxide value is defined as the amount of peroxide oxygen per 1 kilogram of fat or oil. Traditionally this was expressed in units of milliequivalents, although in SI units the appropriate option would be in millimoles per kilogram (N.B. 1 milliequivalents = 0.5 millimole; because 1 mEq of O 2 =1 mmol/2 of O 2 =0.5 mmol of O 2, where 2 is valence).
Many industrial peroxides are produced using hydrogen peroxide. Reactions with aldehydes and ketones yield a series of compounds depending on conditions. Specific reactions include addition of hydrogen peroxide across the C=O double bond: R 2 C=O + H 2 O 2 → R 2 C(OH)OOH. In some cases, these hydroperoxides convert to give cyclic diperoxides: