It may be obtained in the spongy form by igniting iridium ammonium chloride, and this variety of the metal readily oxidizes when heated in air.
It is a black amorphous powder soluble in concentrated sulphuric and hydrochloric acids, and when in the moist state readily oxidizes on exposure.
It is formed by reducing diortho-dinitrodiphenyl with sodium amalgam and methyl alcohol, or by heating diphenylene-ortho-dihydrazine with hydrochloric acid to 150° C. It crystallizes in needles which melt at 156° C. Potassium permanganate oxidizes it to pyridazine tetracarboxylic acid.
In alkaline solution, potassium permanganate oxidizes it to inactive tartaric acid and carbon dioxide (0.
Potassium phenolate, C 6 H 5 OK, crystallizes in fine needles, is very hygroscopic and oxidizes rapidly on exposure.
This solution is not very stable, since on exposure to air it slowly oxidizes and becomes turbid owing to the gradual precipitation of sulphur.
This solution possesses reducing properties,and gradually oxidizes to sulphuric acid on exposure.
It crystallizes in monoclinic tables which melt at 148-149° C. Chromic acid oxidizes it to pyrene quinone, C16H802, and pyrenic acid, C15H1806.
Carbon bisulphide slowly oxidizes on exposure to air, but by the action of potassium permanganate or chromic acid it is readily oxidized to carbon dioxide and sulphuric acid.
It fuses easily in the electric arc. It oxidizes superficially when heated, but fairly rapidly when ignited in an oxidizing blowpipe flame, forming a black smoke of the oxide.
Chromic acid oxidizes it to benzoic acid; zinc and acetic acid reduce it to cinnamic acid, C 6 H 5 CH:CH CO 2 H, whilst sodium amalgam reduces it to hydrocinnamic acid, C6H5 CH2 C02H.
More important are Kekule's observations that nitrous acid oxidizes pyrocatechol or [I.2]-dioxybenzene, and protocatechuic acid or [3.4]- dioxybenzoic acid to dioxytartaric acid, (C(OH) 2 COOH) 2 (Ann., 1883, 221, p. 230); and 0.
This substance is transformed into hexachlor-R-pentene oxycarboxylic acid (3) when digested with water; and chromic acid oxidizes this substance to hexachlor-R-pentene (4).
Bromine water oxidizes this substance to oxalic acid and tetrabromdichloracetone (5).
Potassium persulphate oxidizes it in alkaline solution, the product on boiling with acids giving hydroquiirone carboxylic acid (German Patent 81,297).
Bromine oxidizes it to nitric acid, but the reaction is not quantitative.
In acid solution, potassium permanganate oxidizes it to nitric acid, but in alkaline solution only to nitrous acid.
After it has been melted down and brought to a red heat, the blast, admitted at the back, oxidizes the lead and drives the litharge formed towards the front, where it is run off.
Heating or exposure to sunlight reduces it to the red oxide; it fires when ground with sulphur, and oxidizes ammonia to nitric acid, with the simultaneous formation of ammonium nitrate.
It oxidizes a manganese salt (free from chlorine) in the presence of nitric acid to a permanganate; this is a very delicate test for manganese.
Chem., 9, p. 405; To, p. Chromic acid oxidizes phenanthrene, first to phenanthrene-quinone, and then to diphenic acid, HO 2 C C 6 H 4 C 6 H 4 C02H.
Briihl) and boiling point 104° C. Dilute acids readily transform it into alcohol and aldehyde, and chromic acid oxidizes it to acetic acid.
It oxidizes readily: exposure to air giving acrylic acid, nitric acid giving oxalic acid, bichromate of potash and sulphuric acid giving carbon dioxide and formic acid.
It is a colourless aromatic-smelling oily liquid, which boils at 247° C. and readily oxidizes on exposure.
On oxidation with potassium permanganate it gives homovanillin, vanillin, &c.; with chromic acid in acetic acid solution it is converted into carbon dioxide and acetic acid, whilst nitric acid oxidizes it to oxalic acid.
Chromic acid oxidizes it to acetic acid and ozone oxidizes it to ethyl peroxide.
Manganese dioxide and sulphuric acid oxidize it to benzoic and o-phthalic acid; potassium chlorate and sulphuric acid breaks the ring; and ozone oxidizes it to the highly explosive white solid named ozo-benzene, C 6 H 6 O 6.
When heated to about 200° it yields a brown amorphous substance, named caramel, used in colouring liquors, &c. Concentrated sulphuric acid gives a black carbonaceous mass; boiling nitric acid oxidizes it to d-saccharic, tartaric and oxalic acids; and when heated to 160° with acetic anhydride an octa-acetyl ester is produced.
It oxidizes rapidly when exposed to air, and burns when heated in air, oxygen, chlorine, bromine or sulphur vapour.
Potassium bichromate oxidizes it to malonic acid; nitric acid oxidizes it to oxalic acid; and hydriodic acid reduces it to succinic acid.
Potassium permanganate in acid solution oxidizes it to carbon dioxide and water; the manganese sulphate formed has a catalytic accelerating effect on the decomposition.
Chlorine oxidizes it to acetaldehyde, and under certain conditions chloral is formed.
The action proceeds in two stages; in the first hydrogen peroxide and potassium aurocyanide are formed, and in the second the hydrogen peroxide oxidizes a further quantity of gold and potassium cyanide to aurocyanide, thus (1) 2Au+4KCN +02+2H20=2KAu(CN)2+4KOH+H202;(2)2Au+4KCN+2H202= 2KAu(CN) 2 +4KOH.
Chromic acid oxidizes it to retene quinone, phthalic acid and acetic acid.
The metal oxidizes very slowly in dry air at ordinary temperatures, but somewhat more rapidly in moist air or when heated.
Marcasite readily oxidizes on exposure to moist air, with the production of sulphuric acid and a white fibrous efflorescence of ferrous sulphate, and in course of time specimens in collections often became completely disintegrated.
Exposed to moist air it rapidly oxidizes to the hydroxide; and it burns on heating in air with a yellow flame, yielding the monoxide and dioxide.
Dilute potassium permanganate oxidizes the olefines to glycols (G.
Hot concentrated nitric acid oxidizes it to picric acid and oxalic acid, whilst on treatment with hydrochloric acid and potassium chlorate it yields chloranil (tetrachloroquinone).
Quinone-dioxime, HON: C 6 H 4: NOH, crystallizes in colourless or yellow needles, which decompose when heated to about 240° C. Potassium ferrocyanide in alkaline solution oxidizes it to dinitrosobenzene, whilst cold concentrated nitric acid oxidizes it to para-dinitrobenzene.
If wet it oxidizes the products of decomposition.
Nitric acid oxidizes it to benzoic acid and acetic acid.
Zinc and hydrochloric acid in the cold convert it into alloxantin, hydroxylamine gives nitroso-barbituric acid, C 4 H 2 N 2 0 3: NOH, baryta water gives alloxanic acid, C 4 H 4 N 2 0 5, hot dilute nitric acid oxidizes it to parabanic acid, hot potassium hydroxide solution hydrolyses it to urea and mesoxalic acid and zinc and hot hydrochloric acid convert it into dialuric acid, C4H4N204.
It oxidizes arsenites, sulphites and thiosulphates immediately.
It dissolves unchanged in concentrated sulphuric acid, and oxidizes readily in moist air, forming Prussian blue.
The precipitate so obtained is a brown amorphous solid which readily oxidizes on exposure, and is decomposed by heat with liberation of hydrogen and formation of the sesquioxide.
Potash fusion converts it into acetic acid; nitric acid oxidizes it to acetic and oxalic acids; chromic acid mixture to acetaldehyde and acetic acid, and potassium permanganate to a0-dioxybutyric acid.
Potassium permanganate oxidizes it to fry-dioxybutyric acid.
Villiger (Berichte, 1900, 33, pp. 858, 2480) have shown that benzoyl hydrogen peroxide C 6 H 5 CO O OH is formed as an intermediate product and that this oxidizes the indigo compound, being itself reduced to benzoic acid; they have also shown that this peroxide is soluble in benzaldehyde with production of benzoic acid, and it must be assumed that the oxidation of benzaldehyde proceeds as shown in the equations: C 6 H 5 CHO+0 2 = C6H5CO.O.OH, C 6 H 5 CO.
On heating with dilute sulphuric acid it yields acetone, but with the concentrated acid it gives mesitylene, Potassium permanganate oxidizes it to acetic acid and hydroxyisobutyric acid (A.