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.
This acid gives with silver nitrite the corresponding nitromalonic acid, which readily yielded the third nitromethane, CHaHb(N02),Hd, also identical with the first.
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.
Potassium osmiate, K 2 0sO 4 2H 2 0, formed when an alkaline solution of the tetroxide is decomposed by alcohol, or by potassium nitrite, crystallizes in red octahedra.
Ammonium nitrite, NH 4 NO 2, is formed by oxidizing ammonia with ozone or hydrogen peroxide; by precipitating barium or lead nitrites with ammonium sulphate, or silver nitrite with ammonium chloride.
Compounds are known which may be looked upon as derived from ammonia by the replacement of its hydrogen by the sulpho-group (HS0 3); thus potassium ammon-trisulphonate,N(SO 3 K) 3.2H20,is obtained as a crystalline precipitate on the addition of excess of potassium sulphite to a solution of potassium nitrite, KN02+3K2S03+2H20=N(S03K) 3 +4KHO.
442); it may also be prepared by heating the nitrate or nitrite with metallic sodium, free nitrogen being eliminated (German patent, 142467, 1902).
For sodium nitrite see Nitrogen; for sodium nitrate see Saltpetre; for the cyanide see Prussic Acid; and for the borate see Borax.
For the nitrite, see Nitrogen, for the nitrate see Saltpetre and for the cyanide see Prussic Acid; for other salts see the articles wherein the corresponding acid receives treatment.
The potassium salt may be prepared by adding potassium cyanide to ferrous sulphate solution, the brown precipitate so formed being then heated with potassium nitrite: 5 KNC + 2 FeSO 4 = 2 K 2 SO 4 + KFe2(NC)5, 2 KFe 2 (NC) 5 + 2 KNO 2 = 2 FeO + 2 K2Fe(NC)5 NO.
Bamberger (Ber., 1898, 31, p. 455) has shown that the nitro-alkyl derivatives behave as though they possess the constitution of hydrazones, for on heating with dilute alkalies they split more or less readily into an alkaline nitrite and an acid hydrazide: C 6 H 5 NH N: C(N02)CH3+NaOH=NaN02+C6H5NH NH CO CH3.
Nitrite of amyl inhalations are useful in the early stages when the respiratory muscles are freely movable.
With nitrous acid (obtained from amyl nitrite and gaseous hydrochloric acid, the ketone being dissolved in acetic acid) they form isonitroso-ketones, R CO CH:NOH (L.
Pechmann, Ber., 1887, 20, p. 31 12; 1889, 22, p. 2115), CH 3 CO C :(N OH) CH 3 ->CH3 CO C :([[Nhso 3) Ch 3 ->Ch 3 Co - Co Ch]] 3; or by the action of isoamyl nitrite on the isonitrosoketones (0.
In this process the amine salt is dissolved in absolute alcohol and diazotized by the addition of amyl nitrite; a crystalline precipitate of the diazonium salt is formed on standing, or on the addition of a small quantity of ether.
The first aliphatic diazo compound to be isolated was diazoacetic ester, CH N2 CO 2 C 2 H 5 i which is prepared by the action of potassium nitrite on the ethyl ester of glycocoll hydrochloride,HCl NH2 CH2 C02C2H 5 -1-KNO 2 =CHN 2 CO 2 C 2 H 5+ KCI+2H 2 O.
Ethyl nitrite, C2H5.
Amyl nitrite, C5H1, ONO, boils at 96° C. and is used in the preparation of the anhydrous diazonium salts (E.
Freund, Ber., 1895, 28, p. 94 6; 1896, 29, p. 2501), crystallizes in long needles, which melt at 181-183° C. The addition of sodium nitrite to an aqueous solution of its hydrochloride converts it into amido-triaz / N N sulphol S< 1.
Bamberger, Ber., 1893.26, p. 49 6); by the oxidation of nitrosobenzene (below) with atmospheric oxygen; or by the decomposition of benzene diazonium nitrate mercury nitrite, Hg(NO 2) 2.2C 6 H 5 N 2 NO 3, with copper powder (A.
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.
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.
As an example may be taken the use of nitrite of amyl in angina pectoris.