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.
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.
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.
Alkaline potassium permanganate oxidizes it to a-oxyisobutyric acid, (CH 3) 2.
It is a colourless liquid, with a faint aromatic smell, and boils at 206° C. On oxidation with nitric acid it is converted into benzaldehyde, whilst chromic acid oxidizes it to benzoic acid.
Potassium permanganate oxidizes it to f3-oxyisovaleric acid (CH 3) 2 C(OH) CH2.002H, whilst nitric acid gives, among other products, dinitropropane, (CH3)2C(N02)2.
Chromic acid in glacial acetic acid solution oxidizes it to picene-quinone, picene-quinone carboxylic acid, and finally to phthalic acid.
In like manner, if the molten iron in the mixer contains manganese, this metal unites with the sulphur present, and the manganese sulphide, insoluble in the iron, slowly rises to the surface, and as it reaches the air, its sulphur oxidizes to sulphurous acid, which escapes.
The iron oxide thus formed immediately oxidizes these foreign elements, so that the iron is really a carrier of oxygen from air to impurity.
As the iron oxide is stirred into the molten metal laboriously by the workman or "puddler " with his hook or "rabble," it oxidizes the silicon to silica and the phosphorus to phosphoric acid, and unites with both these products, forming with them a basic iron silicate rich in phosphorus, called " puddling " or " tap cinder."
It oxidizes the carbon also, which escapes in purple jets of burning carbonic oxide.
Under normal conditions the silicon oxidizes first.
Then the furnaceman, controlling the decarburization and purification of the molten charge by his examination of test ingots taken from time to time, gradually oxidizes and so removes the foreign elements, and thus brings the metal simultaneously to approximately the composition needed and to a temperature far enough above its present meltingpoint to permit of its being cast into ingots or other castings.
At a relatively low temperature, say 1300° C., the phosphorus of cast iron oxidizes and is removed much faster than its carbon, while at a higher temperature, say 1500° C., carbon oxidizes in preference to phosphorus.