Chocolate brown

Lead(IV) oxide, PbOj. Chocolate brown (electrolytic oxidation of Pb(II) salts). Used as an oxidizing agent. 

Copper(II) ions in aqueous solution are readily obtained from any copper-containing material. The reactions with (a) alkali (p. 430), (b) concentrated ammonia (p 413) and (c) hydrogen sulphide (p. 413) provide satisfactory tests for aqueous copper(II) ions. A further test is to add a hexacyanoferrate(II) (usually as the potassium salt) when a chocolate-brown precipitate of copper(II) hexacyanoferrate(II) is obtained ... 

If cold saturated ethanolic solutions of the recrystallised tetrahydrocarbazole and of picric acid are mixed and stirred, the chocolate-brown picrate of the carbazole slowly crystallises. After it has been filtered off at the pump, washed with a small quantity of ethanol, and dried, it has m.p. 145-146°. 

Tungsten trisulfide [12125-19-8] chocolate-brown powder, slightly soluble in cold water, but readily forming a colloidal solution in hot... 

Arsenates are oxidizing agents and are reduced by concentrated hydrochloric acid or sulfur dioxide. Treatment of a solution of orthoarsenate with silver nitrate in neutral solution results in the formation of a chocolate-brown precipitate of silver orthoarsenate, Ag AsO, which may be used as a test to distinguish arsenates from phosphates. With hydrofluoric acid, orthoarsenate solutions yield hexafluoroarsenates, eg, potassium hexafluoroarsenate [17029-22-0] (KAsFg)2 H2O. Arsenates of calcium or lead are used as insecticides sodium arsenate is used in printing inks and as a mordant. 

Bismuth pentafluoride is an active fluorinating agent. It reacts explosively with water to form ozone, oxygen difluoride, and a voluminous chocolate-brown precipitate, possibly a hydrated bismuth(V) oxyfluoride. A similar brown precipitate is observed when the white soHd compound bismuth oxytrifluoride [66172-91 -6] BiOF, is hydrolyzed. Upon standing, the chocolate-brown precipitate slowly undergoes reduction to yield a white bismuth(Ill) compound. At room temperature BiF reacts vigorously with iodine or sulfur above 50°C it converts paraffin oil to fluorocarbons at 150°C it fluorinates uranium tetrafluoride to uranium pentafluoride and at 180°C it converts Br2 to bromine trifluoride, BrF, and bromine pentafluoride, BrF, and chlorine to chlorine fluoride, GIF. It apparently does not react with dry oxygen. 

Dehydrothalictrifoline (item 29 list, p. 172) was isolated as the quaternary chloride, chocolate-brown, stout prisms, m.p. 271°, which was reduced by zinc in boiling dilute hydrochloric acid to dZ-thalictrifoline, m.p. 151°, identical with that described above. " ... 

Brown HT (El55, Cl Food Brown 3, Chocolate brown) is a bis azo dye, with the chemical name disodium 4,4 -(2,4-dihydroxy-5-hydroxymethyl-l,3-phenylene-bisazo) di(naphthalene-l-sulfonate). The calcium and potassium salts are also permitted. Brown HT is a reddish-brown powder or granules, soluble in water, insoluble in ethanol, with a maximum absorption in water at 460 nm, pH 7, = 403). 

Clinical cyanosis (chocolate brown blood) no hypoxic symptoms... 

One by one Kohnstamm succeeded with the colors. By November, it had four colors in large batches for which it had sent certificates to the Board. By the new year, it was sufficiently confident of success that on January 26, 1909 it announced to the trade that it was ready to accept orders for certified colors. Initially, orders would be accepted for the colors only as compounded into Kohnstamm s well established customary color mixtures which sold under names such as "auramine" and "chocolate brown," rather than as Hesse had hoped, as pure dyes (42,43). 

Symptoms Round, chocolate-brown spots on leaves, stems, pods, and seed coats. These may merge until totally blackened parts of the plant die. 

Arsenic acid reacts with metal salts forming their orthoarsenates, e.g., calcium orthoarsenate. Reaction with silver nitrate in neutral solution produces a chocolate-brown precipitate of silver orthoarsenate. It forms pyroarsenic acid (or pyroarsenate) on heating over 100°C. It is reduced to arsenous acid (or arsenites) when treated with reducing agents. 

The basic chromates are crystals having colors that vary from yellow to chocolate-brown to lilac, depending on their compositions and chromate to hydroxide molar ratios. They lose water when heated at 260°C, are insoluble in water, and are soluble in nitric acid. 

Cupric ferrocyanide, also known as copper(II) hexacyanoferrate(II) or cop-per(ll) hexakis(cyanoferrate(3-)) Cu2Fe(CN)6, is obtained as a chocolate-brown precipitate by the addition of a copperfll) salt solution to ferrocyanide ... 

The kukersites mined from the Estonia deposit have a light chocolate-brown colour in dry condition (10YR 6/4, i.e., light yellowish brown Munsell Color Company 1994), with a conchoidal fracture oblique to the lamination. The density is less than 2.1 g/cm3, but varies depending on the content of clastic material and carbonate minerals versus organic matter. 

The mechanism of the scaling of iron is so complex as to require special mention. Above 570 °C, wiistite (Fei xO) is thermodynamically stable and forms the relatively thick basal layer in the oxide film. This is followed by a magnetite (FesCU) layer which is followed by a final layer of Fe2C>3. Magnetite itself tends to become nonstoichiometric under oxidizing conditions, with excess Fe3+, so that its composition and color can vary from Fe3.oooC>4 (black) toward cubic Fe2.667 04 (i.e., 7-Fe203, chocolate brown). Thus, as outlined in Section 4.6, the oxidation of iron above 570 °C involves mainly... 

Tellurium Dibromide, TeBr2.—Just as the tetrachloride can be reduced to the dichloride, so can tellurium tetrabromide be made to yield the dibromide by treatment in dry ether solution in the dark with finely divided tellurium. The solution so obtained is chocolate-brown in colour and is decomposed by water 8... 

Ash Content. The ash percentages vary from 8.8 to 18.9% in Seam 4 and from 8.04 to 16.88% in Seam 2, the average ash content being 13.21% for the two seams. The ash content is relatively more in Seam 4 than in Seam 2. The ash colors vary from ash-gray and bluish-gray to brown and chocolate brown. 

Arsenic Moniodide ( ), Asl, was described 5 as a chocolate-brown substance resulting from the action of an excess of arsine on an alcoholic solution of iodine, and Schiff6 claimed to have obtained it by the addition of boiling alcohol to arsenic trianilino-triiodide. The identity of these products has not been confirmed. 

The filtrate is run into an equal volume of 48% hydrobromic acid. The chocolate-brown monohydrate of the desired product is precipitated this is filtered off, pressed well, and dried for one hour at 110°C to remove the water of hydration. Olive powder. 

Chocolate brown HT E 156 20285 A Di sodium-4,4 -(2,4-dihydroxy-5-hydroxymethyl-l,3-phenylene bisazo)di(naphthalene-l-sulfonate) C27H18N4Na209S2 652.57 460... 

Chocolate brown HT 20 Insoluble Very good Good Good Good ... 

The use of polyamide is advantageous because it separates natural from synthetic coloring material, removes sugars, acids, and flavoring materials, and concentrates dilute solutions of colors (156,167). However, the use of polyamide is not applicable to chocolate brown FB, chocolate brown HT, or indigotine, because the two chocolate browns are not completely eluted from the column and indigotine decomposes during extraction (157). 

Obsidian from the Alca source is of excellent quality. The glassy matrix is very uniform and easy to use for tool manufacture. Large nodules measuring up to 20-30 cm length are widely available at the main deposit. Smaller nodules are common in neaiby streams. Alca obsidian comes in a range of colors from black, chocolate-brown, to a rare aqua blue (45). 

Rough brain/cauliflower-like, white/dirty cream sometimes colony top chocolate brown or smooth creamy pearl shape Mixture of cell shapes and sizes (budding). Hatshaped ascospores Pichia anomala... 

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