Hydrogen peroxide – heavy polar bluish liquid with a temperature of melting of T ˚ (square) =-0, 41˚C and temperature of boiling of T ˚ (kip.) =150.2˚C. Liquid H2O2 peroxide has density 1.45 г/см^3. In life and laboratory conditions usually use 30% water solution (pergidrol) or 3% solution of substance.
Instruction
1. Molecules H2O2 in liquid state are strongly associated, thanks to existence between them hydrogen communications. As at hydrogen peroxide more hydrogen communications, than at water (more atoms of oxygen are the share of each atom of hydrogen), its density, viscosity and temperature of boiling, respectively, higher can be formed. It mixes up with water in every respect, and pure peroxide and the concentrated its solutions on light explode.
2. At the room temperature of H2O2 catalystically decays with release of atomic oxygen, than its use in medicine as the disinfecting means is caused. Usually take 3% solution antiseptics.
3. In the industry hydrogen peroxide is received in reactions with organic matter, including, for example, at catalytic oxidation of isopropyl alcohol: (CH3)2CHOH+O2=(CH3)2CO+H2O2. (CH3)2CO acetone is a valuable by-product of such reaction.
4. Also H2O2 receive commercially electrolysis of sulfuric acid. During this process, nadserny acid which subsequent decomposition gives peroxide and sulfuric acid is formed.
5. The laboratory receives peroxide usually at effect of the diluted sulfuric acid on barium peroxide: BaO2+H2SO4 (razb.) =BaSO4 ↓+H2O2. Insoluble sulfate of barium drops out in a deposit.
6. Solution of peroxide has sour reaction of the environment. This results from the fact that molecules H2O2 dissociate as weak acid: H2O2↔H (+)+ (HO2) (-). A constant of dissociation H2O2 – 1.5∙10^ (-12).
7. Showing properties of acid, hydrogen peroxide interacts with the bases: H2O2+Ba(OH)2=BaO2+2H2O.
8. Peroxides of some metals, such as BaO2, Na2O2, it is possible to consider as hydrogen peroxide salts – weak acid. From them just also receive in vitro H2O2 effect of stronger acids (for example, a chamois) which are forcing out peroxide.
9. Hydrogen peroxide can react three types: without change of peroxide group, as reducer or as oxidizer. The last type of reactions is most characteristic of H2O2. Examples: Ba(OH)2+H2O2=BaO2+2H2O,2KMnO4+5H2O2+3H2SO4=2MnSO4+K2SO4+5O2+8H2O,PbS+4H2O2=PbSO4+4H2O.
10. Hydrogen peroxide finds broad application. From it receive the bleaches entered into synthetic detergents, various organic peroxides; it is used in polymerization reactions, for restoration of pictures on the basis of lead paints and for receiving antiseptics.