Considering derivatives primarily concerned with transformations of the hydroxyl group, we may regard our typical acid as a fusion of a radical R CO - (named acetyl, propionyl, butyl, &c., generally according to the name of the hydrocarbon containing the same number of carbon atoms) and a hydroxyl group. By replacing the hydroxyl group by a halogen, acid-haloids result; by the elimination of the elements of water between two molecules, acid-anhydrides, which may be oxidized to acid-peroxides; by replacing the hydroxyl group by the group. SH, thio-acids; by replacing it by the amino group, acid-amides (q.v.); by replacing it by the group - NH NH2, acid-hydrazides.
Oxygen, recognized by its power of igniting a glowing splinter, results from the decomposition of oxides of the noble metals, peroxides, chlorates, nitrates and other highly oxygenized salts.
Lead and manganese are partially separated as peroxides, but the remaining metals are not deposited from acid solutions.
It combines directly with chlorine to form sulphuryl chloride and also with many metallic peroxides, converting them into sulphates.
Sodium percarbonates of the formulae Na 2 CO 4, Na2C206, Na 2 C05, NaHCO 4 (two isomers) are obtained by the action of gaseous or solid carbon dioxide on the peroxides Na 2 0 2, Na 2 0 3, NaHO 2 (two isomers)in the presence of water at a low temperature (R.Wolffenstein and E.Peltner, Ber., 1908, 41, pp. 275, 280).
The metal is soluble in solutions of chlorine, bromine, thiosulphates and cyanides; and also in solutions which generate chlorine, such as mixtures of hydrochloric acid with nitric acid, chromic acid, antimonious acid, peroxides and nitrates, and of nitric acid with a chloride.
Oxygen may be prepared by heating mercuric oxide; by strongly heating manganese dioxide and many other peroxides; by heating the oxides of precious metals; and by heating many oxy-acids and oxy-salts to high temperatures, for example, nitric acid, sulphuric acid, nitre, lead nitrate, zinc sulphate, potassium chlorate, &c. Potassium chlorate is generally used and the reaction is accelerated and carried out at a lower temperature by previously mixing the salt with about one-third of its weight of manganese dioxide, which acts as a catalytic agent.
This can be done most easily by " active " oxygen, such as is present in the peroxides, in chromic or permanganic acid.
They behave as unsaturated compounds, combining with oxygen to form peroxides and with the halogens to form triarylmethane halides.
To celebrate his seventieth birthday his scientific papers were collected and published in two volumes (Gesammelte Werke, Brunswick, 1905), and the names of the headings under which they are grouped give some idea of the range and extent of his chemical work: (1) organic arsenic compounds, (2) uric acid group, (3) indigo, (4) papers arising from indigo researches, (5) pyrrol and pyridine bases, (6) experiments on the elimination of water and on condensation, (7) the phthaleins, (8) the hydro-aromatic compounds, (9) the terpenes, (io) nitroso compounds, (11) furfurol, (12) acetylene compounds and "strain" (Spannungs) theory, (13) peroxides, (14) basic properties of oxygen, (15) dibenzalacetone and triphenylamine, (16) various researches on the aromatic and (17) the aliphatic series.
Five species of oxides may be distinguished: (I) basic oxides, (2) acidic oxides, (3) neutral oxides, (4) peroxides, (5) mixed anhydrides and salts.
Peroxides may in most cases be defined as oxides containing more oxygen than the typical oxide.
All peroxides have oxidizing properties.
Pb0+503) Two species of basic peroxides may be distinguished: (I) the superoxides or peroxidates, containing the oxygen atoms in a chain, e.g.
Acidic peroxides combine with basic oxides to form "per" salts, and by loss of oxygen yield the acidic oxide typical of the element.
The important oxidizing agents include: oxygen, ozone, peroxides, the halogens chlorine and bromine, oxyacids such as nitric and those of chlorine, bromine and iodine, and also chromic and permanganic acid.
Peroxides may be basic or acidic. Some basic oxides yield hydrogen peroxide with acids, others yield oxygen (these also liberate chlorine from hydrochloric acid), and may combine with lower acidic oxides to form salts of the normal basic oxide with the higher acidic oxide.