Ferrous hypophosphite

Ferrous hypophosphite, Fe(H2P02)2, results on dissolving iron in hypophosphorous acid, air being carefully excluded.2 The metal dissolves with evolution of hydrogen gas, and the salt passes into solution. It is also obtained by double decomposition of solutions of ferrous sulphate and the barium salt.3 Ferrous hypophosphite crystallises m green octahedra, which readily oxidise on exposure to air. 

L. P. de St. Gilles, and I. M. Kolthoff, found that potassium permanganate oxidizes hypophosphorous acid completely to phosphoric acid. L. Amat found that the oxidation proceeds more quickly the more cone, the soln., the more acidic the soln., and the higher the temp. at ordinary temp., and in dil. soln., the oxidation is incomplete. If the soln. be too hot, some permanganate may be decomposed without interaction with the hypophosphorous acid. The reaction was studied by I. M. Kolthoff. M. Major, and A. Sieverts found that reduced iron readily dissolves in a hot soln. of sodium hypophosphite ferric salts are reduced to the ferrous state and ferric alum reacts at the temp, of the water-bath, while phosphorous acid is not attacked after several hours. 

M. Major studied the reduction of iron alum by hypophosphites. A. D. Mitchell found that a considerable error is caused by the presence of hypophosphorous acid when ferrous salts are titrated by potassium dichromate. This is tentatively ascribed to the ferrous salt acting as inductor in the oxidation of hypophosphorous acid by chromic acid, probably in virtue of the transient formation... 

Colorless, slightly acid liq. d about 1.00. Foams in the mouth, Keep protected from light and in a cool place. In-compat Alkalies, ammonia and their carbonates, albumin, balsam Peru, phenol, charcoal, chlorides, alkali citrates ferrous, mercurous or gold salts hypophosphites, iodides, lime water, permanganates, sulfites, tinctures, and organic matter in general. 

Incompal. Alcohol, arsenites, bromides, iodides, hydrochloric acid, charcoal organic substances generally ferrous or mercurous salts, hypophosphites, hyposulfites, sulfites, peroxides, oxalates. 

There is now abundant evidence for the homolytic decomposition of covalent azo- and diazo-compounds of many types, but evidence for one-electron transfer reactions of diazonium salts is very scanty. Cooper (4) and Marvel ( ) have shown that reduction of diazonium salts by ferrous ions can initiate.vinyl polymerization, while Kornblum s work ( ) has shown that the reduction of diazonium salts by hypophosphite is promoted by oxidizing agents in a manner indicative of the chain reaction ... 

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