General orange

The dichromate(VI) salts may be obtained by the addition of acid to the chromate(VI) salts. However, they are better prepared by adding one-half the acid equivalent of a metal hydrate, oxide, or carbonate to an aqueous solution of CrO, then removing the water and/or CO2. Most dichromates(VI) are water-soluble, and the salts contain water(s) of hydration. However, the normal salts of K, Cs, and Rb are anhydrous. Dichromate(VI) compounds of the colorless cations are generally orange-red. The geometry of Ci2 is described as two tetrahedral CrO linked by the shared odd oxygen (72). 

In addition, 9 -cyclohexylaminobenzo[a]fluoran (28),24 lO -cyclohexyl-benzo[c]fluoran (29),24 etc. develop red color, despite the secondary amino group that contributes generally orange color. 

Anthraquinone itself has only a slight yellow colour, while all its hydroxyl derivatives have a more or less marked colour, generally orange-yellow to red. The solutions of the alkali-salts are... 

Some fillers are hazardous materials and require special handling and processing. Below are listed some fillers that are used or can readily be used in composite materials, classified according to the principal characteristics accepted in the industry. The indexes mean no hazard, 0 slight hazard, 1 moderate, 2 severe, 3 extreme hazard, 4. Storage area codes general, orange special, blue hazardous, red. 

Fig. 22 The TLC synopsis shows the apigenin-C-glycosides (e.g. vitexin, isovitexin) with generally green and the luteolin-C-glycosides (e.g. orientin) with generally orange fluorescence.

A mechanism for cycloaddition on anthocyanins involving various yeast metabolites was demonstrated by Cameira dos Santos et al. (1996). This consists of a cycloaddition between a flavylium and compounds with a polarized double bond. The new pigments formed are generally orange, stable and insensitive to variations in both pH and sulfur dioxide. 

The tendency of the color to become darker with time is often indicative of chemical degradation. The test is conducted with the aid of a colorimeter (NF T 60-104 and ASTM D 1500) and by comparison with colored glass standards. The scale varies from 0.5 to 8. The French specifications stipulate that diesel fuel color should be less than 5, which corresponds to an orange-brown tint. Generally, commercial products are light yellow with indices from 1 to 2. 

Molybdate orange and red are pigments (qv) that contain lead(II) molybdate [10190-33-3], PbMoO, formulated in mixed phases with PbCrO and PbSO. The mixed phase is more intensely colored than any of the component phases. Concerns about lead content are lessening the use of these materials (see also Paint). Various organic dyes are precipitated with heteropolymolybdates. This process allows the fixation of the dye in various fabrics. The molybdenum anion generally imparts light stabiHty to the colorant as weU (91). 

Niobium Pent chloride. Niobium pentachloride can be prepared in a variety of ways but most easily by direct chlorination of niobium metal. The reaction takes place at 300—350°C. Chlorination of a niobium pentoxide—carbon mixture also yields the pentachloride however, generally the latter is contaminated with niobium oxide trichloride. The pentachloride is a lemon-yeUow crystalline soHd that melts to a red-orange Hquid and hydrolyzes readily to hydrochloric acid and niobic acid. It is soluble in concentrated hydrochloric and sulfuric acids, sulfur monochloride, and many organic solvents. 

Stilbene dyes have generally been important as direct dyes and fluorescent brighteners for ceUulosic fibers (4). Most stilbene dyes are yeUow and orange, with some examples of reds and browns and even a few blues. Brown stilbene dyes have commercial value as leather dyes (4). 

OIL SOLUBLE AZO DYES The oil soluble, water-iasoluble, azo dyes dissolve ia oils, fats, waxes, etc. Generally, yellow, orange, red, and brown oil colors are azo stmctures and greens, blues, and violets are primarily anthraquiaones (see Dyes, anthraquinone). Blacks are usually nigrosiaes and iaduhnes of the aziae type (see Azinedyes). An example is Oil Red [85-83-6] (127) (Cl Solvent Red 24 Cl 26105). Uses iaclude the coloring of hydrocarbons, waxes, oils, candles, etc. 

Paprika and its oleoresin are approved for use in foods in general where its appHcation as a color additive frequendy ovedaps its use as a spice. Both products have good tinctorial strength and are used at 0.2—100 ppm to produce orange to bright red shades. 

In general, the azo colors are useful for coloring polystyrene, phenoHcs, and rigid poly(vinyl chloride). Many are compatible with poly(methyl methacrylate), but in this case the weatherabiUty of the resin far exceeds the life of the dyes. Among the more widely used azo dyes (qv) are Solvent Yellows 14 and 72 Orange 7 and Reds 1, 24, and 26. 

The submitters report that after approximately 1 hr some lead(Il) acetate is deposited as an orange-red gum which may temporarily restrict the motion of the stirring bar this was not observed by the checkers. The material generally crystallizes after a short period as a white solid. 

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