Nitric arid

The last-named authority has remarked with reference to British gum prepared by sulphuric acid, that it possesses the disadvantageous property of being deliquescent. This method is, therefore, never employed, as besides this, the products are often colored. He also states that when nitric arid is employed in the preparation of dextrin, it must be perfectly pwe. Commercial nitrio acid, as obtained by the action of oil of vitriol upon nitrats of Soda, always contains a small amount of chlorine and although this element is contained in diminished proportion in the dextrin, it is nevertheless sufficient to considerably lessen the brilliancy of the colors prepared with the dextrin. Several printers upon paper and vegetal tissues have observed this, but have been unable to account for it otherwise than by attributing it to the iaferior quality of the gum. 

After separation of the nitroglycerine, the following remain in the spent acid nitroglycerine, dinitroglycerine, mixed esters of sulphuric and nitric arid. The two latter esters react slowly with the nitric arid contained in the waste arid to form further nitroglycerine, which floats on the surface of the arid. 

In a plant of this type nitric arid of about 90% and sulphuric acid of 70% are obtained. In the absorption towers nitric acid of 30-60% is produced. 

The denitration system works satisfactorily only for spent acid from the nitration of glycerine and similar alcohols. In spent acid from trinitrotoluene production the high content of dissolved nitrated hydrocarbons causes an excessive reduction of nitric arid at the top of the denitrating tower. Thus spent acid from the nitration... 

The maximum nitrogen content of nitrocellulose was reached in these experiments when a 5% solutions of sodium, potassium or ammonium nitrate in nitric arid were used. The highest nitrogen percentage, i.e. 13.5%, was attained when using anhydrous salts that readily form hydrates, namely magnesium nitrate, Mg(N03)2, and sodium sulphate, NajSO ... 

Pinck [53] examined the nitrating activity of such a mixture, and obtained nitrocellulose with various nitrogen contents, rising to 13.36%, when nitric arid containing 15% N204 mixed with 95% sulphuric acid was used. 

Phosphorous mid Phosphoric Acids, I lent I gin. uF hydro-bromic acid with I rr. of nitric arid ti boiling, allow to mol. and then add I cc. of nunntniiu wider followed bv t dtv of magnesium sulphate solution. No precipitate should limn oven on. standing two hours. 

Worsnop, D.R Fox, L.E., Zahniser, M.S., and Wofsy, S.C. (1993) Vapor pressures of solid hydrates of nitric arid implications for polar stratospheric clouds. Science 259,71-74. 

Marti, J., and Mauersberger, K. (1994) Evidence for nitric arid pentahydrate formed under stratospheric conditions, J. Phys. Chem. 98,6897-6899. 

Determination of the Copper and Zinc.—One or more tins are emptied into the feeder of a mincing machine and the whole thoroughly triturated, 100 grams being then dried in an oven and carefully incinerated and the ash heated with excess of cone, nitric acid and evaporated on a water-bath until the arid is completely expelled. The residue is heated with distilled water and a drop of dilute nitric arid, the liquid bring filtered and any carbonaceous residue on the filter well washed with water. 

To a solution of 9 grams of 2-methyl-4-hydroxyphenylarsinic acid in 30 c.c. of concentrated sulphuric acid, a mixture of 7 grams of nitric arid (density 1-4) and 10 c.c. of concentrated sulphuric arid is added dropwise, the temperature being maintrined at about —5 C. during the operation. 

The oxyddorwirinn of benzene by an aqueous solution of hydrochloric arid takes place in this case m the liquid phase, in an agitated reactor, around 135 C and between 1 and 13.106 Pa absolute, in the presence of oxygen and nitric arid. Benzene once-through conversion is better than 80 per cent, and monochlorobenzene selectivity is better than 90 molar per cent. The reactor output is settled to produce two phases ... 

This takes place in the iiqtnd phase, at 80°C, under 3.106 Pa absolute, in the presence of a palladium- and teUarinm-based catalyst deposited on activated charcoal and activated by nitric arid. Butadiene and make-up and recycle acetic arid are introduced at the same time as compressed air at the base of the reaction system. The freshly prepared catalyst is kept in suspension in recycle acetic acid in a separate agitated vessel. It is continuously added near the top of the reactor. Residence time is about 2 h. 

Copper and silver will dissolve in nitric arid or hot sulfuric acid. A mixture of hydrochloric and nitric acids (aqua regia) will dissolve gold. It has recently been reported that mixtures of halogens and quaternary ammonium halides in organic solvents dissolve gold faster than does aqua regia sec Nakao, Y. J. Chem. Soc. Chem. Commun. 1992,426-427. 

Preparation.—By treating anenioua anhydride with nitric arid —... 

Preparation.—1. By the action of nitric arid containing a little hydrochloric acid an metallic antimony... 

PnjpamtfM. —By the action of oxidising substances, auoh as chlorine and nitric arid, on potawic ferrocyanide r— > + a. - K KCy., + 3KC1. 

A second method is to evaporate down urine to a yrapy consistency, and tlien add pure nitric arid, when mtrate of urea separates out as a cryrinhine powder, which is decomposed on the addition of potassium carbonate, with formaticm of potassium nitrate and free urea. TIrese bodies can then he eamly separated by treatment with alcohol, in W hioh the urea dissolves. A third method is that reconnnended by Berzelius a concentrated solution of oxalic arid is added to the evaporated utin when a precipitate of the insoluble oxalate of urea is thrown down this is boiled with chalk, when the pure urea is left in solution. 

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