Hydrogen dioxid

Exists naturally in very minute quantity in rain-water, in air and in the saliva. 

This substance may be obtained in a state of purity by accurately following the process of Thenard. It may also be obtained, mixed with a large quantity of HaO, by the action of carbon dioxid on barium perliydroxid BaOaHa - - COa = BaCOa - - HaOa or of dilute sulfuric acid on barium peroxid BaOa -f HaSOa = BaS04 + HaOa. It is also formed in small quantity during the slow oxidation of many elements and compounds, such as P, Pb, Zn, Cd, Al, alcohol, ether, and the essences. 

It is prepared industrially of 10-12 volume strength by gradually adding barium peroxid to dilute hydrofluoric acid solution, the mixture being maintained at a low temperature and constantly agitated. 

The pure substance is a colorless, syrupy liquid, which, when poured into HjO, sinks under it before mixing. It has a disagreeable, metallic taste, somewhat resembling that of tartar emetic. When taken into the mouth it produces a tingling sensation, increases the flow of saliva, and bleaches the tissues with which it comes in contact. It is still liquid at —SO ( —23° F.). It is very unstable, and, even in darkness and at ordinary temperature, is gradually decomposed. At 20° (68° F.) the decomposition takes. 

The pure substance, when decomposed, yields 475 times its volume of oxygen the dilute 15 to 20 volumes. 

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Structure H—0—0—H, covalently bound, nonpolar molecule. Synonyms hydrogen dioxide perone hydroperoxide. 

C-H bond oxygen insertion, 1163 configuration retention, 1163 epoxidation, 1144-50 hydroperoxy anion transfer, 382 Steric effects hydrogen dioxide, 96-7 peroxide dihedral angle, 101, 177 Steric strain... 

Sodium hydrogen dioxide remains as a white powder on shaking pulverulent sodium dioxide with an ice-cold mixture of alcohol and cone, hydrochloric, nitric,... 

Synonyms Dihydrogen dioxide hydrogen dioxide hydrogen oxide hydroperoxide peroxide... 

Acyl chloride Sulfur Hydrogen dioxide chloride... 

L. Pasteur, J. Tyndall, E. T. Chapman, P. Miquel, W. Spring, F. Schulz, etc. Air may be freed from dust particles, etc., in suspension by filtration through biscuit earthenware, asbestos, or cotton wool. When a beam of sunlight is passed through unfiltered air, it reveals a multitude of motes constantly in motion. Lucretius, in his Be natura remm (2.113, 60 b.c.), has given a very vivid description of the phenomenon. With filtered air, there is no such eflect, and J. Tyndall said that such air is optically empty. F. O. Rice showed that in a number of reactions— e.g. the oxidation of soln. of sodium arsenite or sulphite, the decomposition of hydrogen dioxide, etc.—the suspended dust in air acts as a catalytic agent. 

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