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.
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 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.
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.
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.
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.
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.
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.
For on the one hand knowledge of the fact that nitrite of amyl lessens blood pressure has led to the successful employment of other nitrites and bodies having a similar action, and on the other the knowledge that increased blood pressure tends to cause anginal pain leads to the prohibition of any strain, any food, any exposure to cold, and also of any medicines which would unduly raise the blood pressure.
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.
When the latter have oxidized ammonia to nitrite, however, the former step in and oxidize it still further to nitric acid.
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.
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.
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.
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.
NH 2 NH2 Diorthodiaminodiphenyl, -, isobtained bythe reduction of the corresponding nitro compound (obtained by the action of ethyl nitrite at o° C. on metadinitrobenzidine hydrochloride).
- This group contains amyl nitrite, ethyl nitrite, methyl nitrite, nitroglycerin, sodium and potassium nitrites, erythrol-tetranitrate, and many other compounds containing nitrous or nitric acid.