Hydriodie Acid

Salts of hydrobromic and hydriodie acid produce similar results. 

Triethylenediamino-chromic Iodide, [Cr en.3JI3.H2O, is obtained from the chloride by decomposing it with hydriodie acid and recrystallising the product from water. It crystallises in yellow leaflets, which are less soluble in water than either the chloride or the bromide. 

The bromide separates in prismatic needles which are reddish in colour and less soluble than the chloride. The mercury double salt with mercuric iodide is produced by mixing the chloride with mercuric iodide and hydriodie acid. The salt is very sparingly soluble in water and separates as an orange-coloured powder.1... 

The iodide, [Co(NHg)5Cl]I2, is prepared in the same manner as the bromide from the chloride and hydriodie acid. It is much more soluble than the chloride or the bromide, and may be crystallised in brownish-violet oetahedra from a solution of hydriodie acid. 

With sufficiently powerful reducing agents, especially hydriodie acid, sulphur is reducible to hydrogen sulphide, and at higher temperatures a similar reduction can be effected by organic matter generally.9... 

When heated with hydrogen iodide or concentrated aqueous hydriodie acid, sulphur is reduced to hydrogen sulphide, but once more the reaction is incomplete, leading only to an equilibrium mixture ... 

The tetra-iodide may also be formed from the dioxide and concentrated hydriodie acid. Telluric acid gives a similar result. The resulting halide may separate as such or in needles of an additive compound, HI.TeI4.8H20, which gives a residue of tetra-iodide when warmed to 50°— 60° C.5... 

It is sparingly soluble in alcohol and acetone, insoluble in ether, chloroform and carbon disulphide.8 Alkalis and ammonia in aqueous solution readily dissolve it. It is also soluble in a solution of hydriodie acid. 

We hare already seen, however, that equation (ii) becomes reversed in acid medium, and the prevention of this reversal here appears to be due to the removal of the hydriodie acid according to equation (i). 

Twelve grama of cobalt carbonate are dissolved in 45g of 67% hydriodie acid (No, 89), filtered, and added to 22g of pn and 22g of HI in 150ml of water The pink precipitate of cobalt (II) salt that forms is ignored vigorous oxidation with air for three hours rapidly converts it to a yellow product After filtration, the mother liquor is evaporated and two more batches of material are isolated the final volume is about 50mL... 

Ten grains of earbonatopentamrainecobalt (III) nitrate -hydrate (No. 118) are dissolved in 40ml of water at 85°C and 12.5g of finely powdered potassium iodide are added. The solution is cooled to 0°C in ice and the red product is filtered off and drained well This solid is suspended in 25ml of water and 20ml of 28% hydriodie acid is stirred in. When evolution of gas has stopped, 100ml of alcohol are added to the mixture and the... 

Hydriodie acid (HI l is a colorless solulion formed when hydrogen iodide gas is dissolved in waler. commercially ol strength 1() < HI. frequently colored brown by iodine. There is a maximum constant boiling point 127 C (774 mml at 57f HI idistillatcl for mixtures of hydriodie acid and water. Hydriodie acid is u.sed in the preparation of iodides, and us an important reagent in organic chemistry. ... 

Hydriodie acid is made by the reaction tl t ol iodine and hydrosulfurie acid tor sulfurous acidt. (21 oT phosphorus plus iodine plus water, with subsequent distillation in all eases. 

Method I.—10 gms. (1 mol.) of benzophenone, 12 gms. (nearly 2 mols.) of hydriodie acid (B.P. 127°) and 2 gms. (more than 1 atom) of red phosphorus are heated together in a sealed tube for 6 hours at 160° (see p. 41). The reaction mixture is extracted with ether and the extract washed with water several times. It is then filtered, dried over calcium chloride for 24 hours, the ether removed on a water bath and the residue distilled. 

As indicated in connection with iodine tetroxide, N. A. E. Millon observed the formation of what he considered to be nitroso-iodic acid, and H. Kammorer what he considered to be iodine dinitrosyl tetroxide, I204(N0)8, or maybe O I.O.NO, by treating iodine with nitric acid, or nitrosylsulphuric acid. The yellow powder was considered by H. Kappeler to be iodine nitrate, T.NOj, vide 2. 19, 9. E. Briner said that mixtures of nitric and hydriodie acids do not form a univariant system like stabilized aqua regia, for the iodine produced as a result of the primary reaction is oxidized to iodic acid, with the evolution of nitric oxide. 

These compounds are soluble in carbon disulphide, from which they may be obtained as orange or yellow crystals. They are only slightly soluble in other organic solvents such as benzene, chloroform, etc. They can be burnt in air, giving oxides of phosphorus, sulphur and iodine. They are decomposed by warm water or moist air, giving first phosphoric and hydriodie acids, then phosphoric acid and hydrogen sulphide.4... 

General Reactions.—Various products were obtained when phosphorous acid was heated with halogens in a sealed tube. Iodine gave phosphoric and hydriodie acids, phosphonium iodide and an iodide of phosphorus, whilst bromine gave phosphoric acid, phosphorus tribromide and hydrobromie acid.6 A dry ether solution of the acid was not oxidised by bromine or dry palladium black, but oxidation proceeded readily in the presence of moisture.7... 

An alcoholic solution of methylarscuoxide is treated with an exccs.s of hydriodie acid. ... 

Bromo-7 12-dihydroisobenzophenarsazine is obtained from the 7-phenoxy-derivative by heating for four hours under reflux with an excess of concentrated hydrobromic acid. It crystallises from xylene in dark yeUow needles, 3I.pt. 227° C., insoluble in water, but soluble in the usual organic solvents. It is unacted upon by dilute alkalis. Replacing the hydrobromic acid by hydriodie acid, the 7-iodo-7 12-dihydroisobenzophenarsazine is formed in 62 jper cent, yield. It may also be obtained from the corresponding oxide by the action of hydriodie acid. From xylene it separates in beautiful red needles, 3I.pt. 205° C. 

The disposition of the functional groups in a -D-glucosaccharinic acid was also established by Kiliani. Reduction of saceharon with hydriodie acid and red phosphorus gave the known, crystalline DL-(2-methylglutaric... 

When heated to 140° (284° F.), with hydriodie acid under pressure, it is decomposed into caproic acid and ammonia. Nitrous acid converts it into leucio acid, CgHuOs, HaO and N. It unites with acids to form soluble, crystalline salts. It also dissolves readily in solutions of alkaline hydroxlds, forming crystalline compounds with the metallic elements. 

HydiodUoiio and hydriodie acids daeompoae biomk acid in a dmilar manner with formation of the dUoride or iodide of hromina... 

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