This acid gives with silver nitrite the corresponding nitromalonic acid, which readily yielded the third nitromethane, CHaHb(N02),Hd, also identical with the first.
Amyl nitrite, C5H1, ONO, boils at 96° C. and is used in the preparation of the anhydrous diazonium salts (E.
It may be prepared by the addition of potassium nitrite to an acetic acid solution of cobalt chloride.
This salt may be used for the separation of cobalt and nickel, since the latter metal does not form a similar double nitrite, but it is necessary that the alkaline earth metals should be absent, for in their presence nickel forms complex nitrites containing the alkaline earth metal and the alkali metal.
It is now known that the action takes place in two stages; the ammonium salt is first oxidized to the nitrite stage and subsequently to the nitrate.
This readily gave with silver nitrite a nitromethane in which we may suppose the nitro-group to replace the a hydrogen atom, i.e.
This acid with silver nitrite gave nitroacetic acid, which readily gave the second nitromethane, CH a (NO 2) b H c H d, identical with the first nitromethane.
It is also prepared by heating ammonium nitrite (or a mixture of sodium nitrite and ammonium chloride): NH 4 NO 2 =2H20+N21 by heating a mixture of ammonium nitrate and chloride (the chlorine which is simultaneously produced being absorbed by milk of lime or by a solution of sodium hydroxide): 4NH4N03+2NH4C1=5N2 +C1 2 +12H 2 O; by heating ammonium dichromate (or a mixture of ammonium chloride and potassium dichromate): (NH4)2Cr207 = Cr203+4H20+ N2; by passing chlorine into a concentrated solution of ammonia (which should be present in considerable excess): 8NH3+3C12=6NH4C1-F-N2; by the action of hypochlorites or hypobromites on ammonia: 3NaOBr-+2NH 3 =3NaBr+3H 2 OH-N 2; and by the action of manganese dioxide on ammonium nitrate at 180-20o° C. It is also formed by the reduction of nitric and nitrous oxides with hydrogen in the presence of platinized asbestos at a red heat (G.
Nitric acid (up to 50%) is formed in the first tower, and weaker acids in the successive ones; the last tower contains milk of lime which combines with the gases to form calcium nitrite and nitrate (this product, being unsuitable as a manure, is decomposed with the acid, and the evolved gases sent back).
It is also formed by the action of concentrated sulphuric acid on sodium nitrite in the presence of mercury.
News, 23, p. 206) by reducing a solution of potassium nitrite with sodium amalgam, and subsequent precipitation as silver salt.
Sodium nitrite, the most commonly used salt of the acid, is generally obtained by heating the nitrate with metallic lead; by heating sodium nitrate with sulphur and sodium hydroxide, the product then being fractionally crystallized;(Read, Holliday & Sons): 3NaNO 3 +S+2NaOH = Na2S04+3NaN02+H20; by oxidizing atmospheric nitrogen in an electric arc, keeping the gases above 300° C., until absorption in alkaline hydroxide solution is effected (German Pat.
It is also prepared by the action of phosphorus pentachloride on potassium nitrite or on nitrogen peroxide.
It is readily decomposed by water and alkaline hydroxides, yielding a mixture of nitrite and chloride.
The nitrogen-bacteria that concern us here are of two main categories: (I) those that assimilate elementary nitrogen from its solution in sea-water, building it up into combination with carbohydrate as proteid; and (2) those that break down nitrate into nitrite, nitrite into ammonia and ammonia into elementary nitrogen.
Ammonium nitrate and nitrite, for instance, intensify the action of a water on lead.
Aiphatic Nitro Compounds.-The nitroparaffins may be obtained by the action of the alkyl iodides on silver nitrite (V.
Nitroparaffins may also be obtained by the action of sodium nitrite on the a-halogen fatty acids, the a-nitro fatty acids first formed readily eliminating carbon dioxide (H.
Sandmeyer, Ber., 1887, 20, p. 1494) by the action of copper powder on the double salt formed by the addition of potassium mercuric nitrite to diazonium nitrites; and by the oxidation of primary aromatic amines (E.
The pseudo-nitrols, RR':C(NO)(NO 2), may be obtained by the action of nitrous acid on the secondary nitroparaffins; by the action of silver nitrite on such bromnitrosoparaffins as contain the bromine and the nitroso group united to the same carbon atom (0.
Strong or weak solutions of these substances also decompose it, producing some alkali nitrate and nitrite, the cellulose molecule being only partially restored, some quantity undergoing oxidation.
Ammonium hydroxide has no appreciable action at ordinary temperatures, but strong solutions of sodium or potassium hydroxides start a decomposition, with rise of temperature, in which some nitrate and always some nitrite is produced.
Alcoholic solutions of the alkalis also produce much nitrite along with some formate and acetate.
Although a nitrate, its pharmacological actions resemble those of nitrites such as amyl nitrite, taken internally.
The explanation is that in an alkaline medium at body heat nitroglycerin yields a nitrite, probably as a preliminary stage of resolution.
Nitroglycerin shaken up with warm very dilute alkaline solutions, as sodium carbonate, for a few minutes only, always yields sufficient nitrite to give the diazoreaction; and, as stated, strong alkaline solutions always produce some nitrite as one of the decomposition products.
The further oxidation of the nitrite to a nitrate is effected by bacteria belonging to the genus Nitrobacter.
At a red heat it evolves oxygen with the formation of potassium nitrite, which, in turn, decomposes at a higher temperature.
Sodium nitrite, ethyl nitrite, amyl nitrite) cause relaxation of involuntary muscular fibre and therefore relieve the asthmatic attacks, which depend upon spasm of the involuntary muscles in the bronchial tubes.
Saltpetre may be made to act as a nitrite by dissolving it in water in the strength of about fifty grains to the ounce, soaking blotting-paper in the solution and letting the paper dry.
The salt fuses at 316°; at higher temperatures it loses oxygen (more readily than the corresponding potassium salt) with the formation of nitrite which, at very high temperatures, is reduced ultimately to a mixture of peroxide, Na202, and oxide, Na 2 0.
The alcohol is first acted upon with phosphorus and iodine, and the resulting alkyl iodide is treated with silver nitrite, which gives the corresponding nitroalkyl.
The nitro-alkyl is then treated with potassium nitrite dissolved in concentrated potash, and sulphuric acid is added.
Cyclo-heptanol, C,H 13 0H, is formed by the reduction of suberone, and by the action of silver nitrite on the hydrochloride of cyclo- hexanamine (N.
It crystallizes from benzene in prisms, which melt at 97° C. Sodium nitrite in the presence of excess of acid converts it into the corresponding hydroxylic compound flavenol.
With sodium nitrite it forms a water-soluble blue dye, which is turned red by acids, and is used as an indicator, under the name of lacmoid (M.
When the latter have oxidized ammonia to nitrite, however, the former step in and oxidize it still further to nitric acid.
Now we can see the reason for their administration, because the nitrous ether, consisting chiefly of ethyl nitrite, dilates the superficial vessels and thus allows greater escape of heat from the surface; while acetate of ammonia, by acting as a diaphoretic and stimulating the secretion of sweat, increases the loss of heat by evaporation.
As an example may be taken the use of nitrite of amyl in angina pectoris.
Nitrite of amyl has the power of dilating the arteries; it has consequently been employed with much success in lowering the blood pressure and removing the pain in angina pectoris.
Rubidium nitrate, RbNO 3, obtained by the action of nitric acid on the carbonate, crystallizes in needles or prisms and when strongly heated is transformed into a mixture of nitrite and oxide.
Numerous methods have been devised for the separation of nickel and cobalt, the more important of which are: -the cobaltinitrite method by which the cobalt is precipitated in the presence of acetic acid by means of potassium nitrite (the alkaline earth metals must not be present); the cyanide method (J.