Phosphoric arid

The fuiljstances that have been successfully used as smoke agents fall into five main groups, m., smokes that owe their obscuring power to (I) particle of colloidal rr6on suspended in air (II) particles of phosphoric arid (III) sulfuric acid (IV) hydrochloric arid and (V) zinc chloride. 

These techniques operate in accordance with similar principles (Fig. 3.7). The preheated feed, normally heated by heat exchange with the reactor effluent, is introduced in the reactor in a downflow stream. Conversion takes place in the presence of acid catalysts such as phosphoric arid deposited on silica or silico-aluminates. placed in several fixed beds. This arrangement allows effective control of the temperature rise dne to the exothermic nature of the reaction, by the injection between the beds of.a quench liquid consisting of unconverted Ct. The operating conditions are moderate (temperatures average 120°C, limits 50 to 200 C, pressure 1 to 4.10s Pa absolute). The reactor effluent... 

Phosphate rock can be dissolved by several organic and inorganic acids to produce phosphoric acid. The use of nitric acid for this purpose is described in Chapter 13. Commercial nitrophosphate processes produce phosphoric arid that contedns nitrates hence, these pro-... 

Liquid-liquid contacting in a number of solvent extraction steps to obtain a solution of substantially pure phosphoric arid and... 

Figure 11.33. Manufacture of Phosphoric Arid From Elemental Phosphorus.

Phosphoric Arid, Phosphates and Phospbatic Fertilizers. By W. H. W aggaman. 

Dissolve 75 mg 2,4-dinitrophenylhydrazine in a mixture of 25 ml ethanol arid 25 ml or/Ao-phosphoric acid (85%). 

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. 

Salts of this acid have been prepared by treating a solution of an alkah molybdate with a small quantity of phosphoric acid by adding a mineral acid, preferably concentrated nitric acid, to a solution containing a phosphate and a large excess of molybdate or by boiling an aqueous solution of an alkali phosphate saturated with molyb-dic anhydride. The ammonium and potassium salts separate out as deep yellow micro-crystals, but the sodium salt is soluble, arid is obtained by concentrating the solution when it forms yellow efflorescent rhombohedra. These salts have the approximate composition ... 

The nudeo-proteins under the influence of enzymes are successively transformed into nucleins, into nudeic adds, then into xanthin bases, into phosphoric acid, etc. But only the first phase of the transformation, that which corresponds to the formation of protein and nudein, can be realized by p>epsin and trypsin. The nudeins resist the action of the digestive juices, botii gastric arid pancreatic. The transformation of the nucleins first into nucldc adds, then into phosphoric add and into purin bas, is induced in living cells, on the contrary, by the endo-cellular enzymes, which bear the name of nucleases. 

Dissolution of phosphate rock by hydrochloric arid, which results in an aqueous solution of calcium chloride and phosphoric acid ... 

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