Acid, hypophosphorous nitric

EXAMPLE 6.16. Write formulas for the following acids (a) nitric acid, (h) chloric acid, (c) hypophosphorous acid, and (d) perbromic acid. 

Methyl-l 4-arsenobenzene or 2 2 -Dimethyl-l 4 1 4 -diarsenodibenzene is obtained in the usual way by reducing the foregoing diarsinie acid. The acid is heated for three to four hours in a sealed tube with hypophosphorous acid at 190° C. The arseno-compound is an egg-yeUow to orange coloured powder, insoluble in all solvents, and readily oxidised to the diarsinie acid by nitric acid or hydrogen peroxide. 

NITRIC ACID, MERCURY(II) SALT (10045-94-0) A powerful oxidizer. Violent reaction with reducing agents, combustibles, phosphinic acid, hypophosphoric acid, petroleum hydrocarbons. Forms heat- and/or shock-sensitive compounds with acetylene (forms mercury acetylide), ethanol (forms mercury fulminate), ferrocene, isobutene, phosphine, potassium cyanide, sulfur. Incompatible with strong acids, acetic anhydride, ammonia, ammonium hexacyanoferrate(II), organic azides, citric acid, hydrazinium perchlorate. 

J. J. Berzelius made phosphorous acid by treating phosphorous oxide with water —a reaction studied by T. E. Thorpe and A. E. H. Tutton, vide supra. B. D. Steele obtained it by the action of iodine on hypophosphorous acid (q.v.) in the presence of mineral acids and A. Besson, by heating the hemioxide with water in a sealed tube at 100° P20+024-3H20=2H3P0k. Phosphorous acid is also produced by the action of hot dil. nitric acid oh phosphorus the objection to this process, said J. Come, is the simultaneous production of phosphoric acid (q.v.), and this the more, the greater the cone, of the nitric acid. T. Salzer, and J. Philipp also reported that some hypophosphoric acid is produced at the same time. The early workers knew that the aq. soln. of phosphatic acid slowly decomposes, giving off phosphine, hence the faint smell like garlic. C. F. Sehonbein mentioned that freshly prepared phosphatic acid contains a trace of nitric acid as well as ozone. A. Tamm also observed that some phosphorous acid is formed when phosphated steel is dissolved in nitric acid. 

Oxidation of yellow phosphorus by copper nitrate in the presence of nitric acid at about 60° C. also yielded hypophosphoric acid along with phosphoric acid and copper phosphide.4 These reactions have been expressed by the equations... 

S,6-Dimethoxybenzo[c]-l,2,5-oxatellurazoliiiin 3-Oxide Chloride 74 g (0.2 mol) of 3,4-dimethoxyphenyl tellurium trichloride and 200 ml glacial acetic acid are placed into a 1.5-/-Erlenmeyer flask. 18 g (0.2 mol) of 70% nitric acid are gradually added to the stirred mixture. After all the acid has been added, the mixture is stirred at 20° for 1 h. Then 1 /ethanol is added followed by 24 g (0.18 mol) of 50% hypophosphorous acid. Within 30 min red crystals form, which are collected by filtration and recrystallized from absolute ethanol yield 69% m.p. 200°. 

It has already been mentioned, that when hypophosphorous and phosphorous acids are heated, they are resolved into phos-phonc acid and phosphuretted hydrogen. This gas is consequently given off frequently towards the end of the evaporation of a solution of phosphorus in diluted nitric acid, which at first forms phosphorous acid, by the decomposition of which the gas is produced, causing a sudden combustion at the surface of me evaporating liquid. 

The oxide forms colourless crystals, M.pt. 78° to 80° C. When dissolved m acetic acid and treated with hydrochloric acid (density ITS), it yields diphenylchlorostibine, M.pt. 68° C. It is reduced by hypophosphorous acid to tetraphenyldistibine, (CeH5)2Sb.Sb(C6H5)2, a yellow compound. Nitric acid reacts violently with the oxide. Hydrogen peroxide in alkaline-alcoholic solution converts it to di-phenylstibinic acid. 

Elwell and Scholes (14) describe a similar method to determine hydrogen sulphide by photometry. The essential difference is that the sample is dissolved at first in a mixture of nitric and hydrochloric acid. After destroying the nitric and formic acid, the formed sulphate is reduced to hydrogen sulphide by a mixture of hydriodic and hypophosphorous acids. 

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