Chamber crystals

Ditrosonium hydrogen sulphate, chamber crystals, NOHSO4. White solid m.p. 73°C (decomp.). Prepared SO2 and fuming nitric acid. Used in diazotization. 

Formed as an intermediate in the Pb chamber process for sulfuric acid by the reaction of sulfur dioxide, nitrogen trioxide, oxygen and w (chamber crystals) (Refs 1 2). Can be prepd from Ag acid sulfate and nitrosyl bromide (Ref 4)... 

Synonyms nitrosyl sulfate chamber crystals nitroxylsulfuric acid nitroso-sulfuric acid nitrosyl hydrogen sulfate... 

Free nitrosylsulphuric acid actually occurs in the lead chambers only under abnormal conditions of working its separation as chamber crystals is most undesirable from the manufacturer s point of view, as not only does it indicate improper regulation of the process, but it also causes the lead walls of the chambers to be attacked unduly. A solution of violet acid is sometimes obtained at the bottom of the Gay-Lussac tower. 

Nitrosulphonic Acid, Nitrosylsulphuric Acid or Nitroso-sulphuric Acid, NQ2.S02.0H.—In 1806, Clement and Desormcs, during the manufacture of sulphuric acid by the lead chamber process, observed the formation of a crystalline solid, to which the names nitrosulphonic acid and nitrosylsulphuric acid were later given the term chamber crystals, however, is still commonly applied to this acid.6 The composition and nature of the acid were first investigated by Weber,7 and by Michaelis and Schumann.8... 

With the screw clamp open, the pyrites is gently heated with a wing burner in a slow stream of air drawn in by the aspirator. The clamp is then partially closed so that air also passes through the capillary into the nitric add. The pyrites may now be heated more strongly the current of air through the nitric add is adjusted by means of the clamp so that red fumes of nitrogen oxides are always present in the bottle or chamber, If not enough vapor of nitric acid is provided, colorless crystals of nitrosyl sulfuric acid ( chamber crystals ) will form on the walls of the bottle. 

He said that hydroxynitrosylsulphonic acid is produced by the action of sulphur dioxide on nitrous acid in 70 per cent, sulphuric acid as a direct product of the interaction of nitrous and sulphurous acids, and not by the reduction of chamber crystals—nitroxylsulphonic acid—because he supposed that the latter cannot exist in less than 80 per cent, sulphuric acid. This assumption was shown, by W. C. Reynolds and W. H. Taylor, to be unfounded nitroxylsulphonic acid can exist in the presence of even 60 per cent, sulphuric acid. Further, the blue colour produced by the action of sulphurous acid, or other reducing agent, on a nitrite in the presence of a cone, sulphuric acid soln. of a copper salt, was supposed by F. Raschig to be the copper salt of P. Sabatier s acid, whereas, according to W. C. Reynolds and W. H. Taylor, the product is the complex which nitric acid forms with copper sulphate, and studied by W. Manchot, V. Kohlschiitter, etc.— vide supra. The existence of F. Raschig s nitrosylsulphonic acid may therefore be questioned, and the same remark applies to his statement of the identity of P. Sabatier s blue acid with the product of the reaction of nitrous and sulphurous acids in the presence of a copper salt. 

SYNS CHAMBER CRYSTALS NITRO ACID SULFITE NITROSONIUM BISULFITE NITROSYL HYDROGEN SULFATE NITROSYL SULFATE SULFURIC ACID, MONOANHYDRIDE with NITROUS ACID... 

EINECS 231-964-2 Lead chamber crystals Nitro acid sulfte Nitro-sulfonic acid hlitrose Nitrososulfuric acid Nitrosulfonic acid Nitrosylsulfuric acid Nltrosylsulphuric acid Nitroxylsulfuric acid Sulfuric acid, monoanhydride with nitrous acid UN2308 Weber s acid. Used to bleach flour. Crystals dec 73°. 

In the lead chamber process for the manufacture of sulfuric acid, nitric oxide, oxygen (from the air), sulfur dioxide, and water (steam), interact. The nitric oxide acts as the catalyst, and is present at the end of the action, with the sulfuric acid. It acts as oxygen carrier. One of the intermediate compounds which is formed contains nitrogen peroxide (NO2), sulfur dioxide, and water. It may be obtained in crystalline form, known as chamber crystals which have the composition HSQ3NO2, nitro-sulfonic acid, under certain conditions. This substance is decomposed in the presence of an excess of steam or water vapor into sulfuric acid and nitric oxide, or better, nitrogen trioxide, N2O3. While the exact formulation of the intermediate compounds is not simple under the various conditions, the evidence at hand is sufficient to make the existence of at least one intermediate compound certain. 

Nitrosyl sulfuric acid in industry it is also called lead chamber crystals because of its occurrence as an impurity in the chamber process for manufacture of H3SO4. 

G. Lunge at first adopted Davy s theory but Lunge and Berl later adopted a theory proposed by Trautz that a substance H2SNO5 is involved as well as chamber crystals. Raschig thought that the catalyst is ortho-nitrous acid and H2SNO5 is formed ... 

In 1768 Scheele obtained solid nitrososulphuric acid (chamber crystals) in crystals like ice on a window by the action of nitrous fumes on concentrated sulphuric acid it is decomposed on exposure to air. He distinguished clearly in 1770 between potassium carbonate and bicarbonate (alkali fixo crystallisato aere fixo saturato), and he distinguished acid, neutral and basic salts very clearly in 1771. ... 

Clement and Desormes were also the first to observe the formation of chamber crystals that evolved nitric oxide and formed sulfuric acid when added to water. The nitric oxide was then available for recycling. 

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