Yellows Oranges

Tellurium trioxide, TeOa, is an orange yellow powder made by thermal decomposition of telluric(VI) acid Te(OH)g. It is a strong oxidising agent which will, like H2Se04, oxidise hydrogen chloride to chlorine. It dissolves in hot water to give telluric(VI) acid. This is a weak acid and quite different from sulphuric and selenic acids. Two series of salts are known. 

Liquid chlorine dioxide, ClOj, boils at 284 K to give an orange-yellow gas. A very reactive compound, it decomposes readily and violently into its constituents. It is a powerful oxidising agent which has recently found favour as a commercial oxidising agent and as a bleach for wood pulp and flour. In addition, it is used in water sterilisation where, unlike chlorine, it does not produce an unpleasant taste. It is produced when potassium chlorate(V) is treated with concentrated sulphuric acid, the reaction being essentially a disproportionation of chloric(V) acid ... 

Aqueous solutions containing titanium(IV) give an orange-yellow colour on addition of hydrogen peroxide the colour is due to the formation of peroxo-titanium complexes, but the exact nature of these is not known. 

The colour sequence already described, for the reduction of van-adium(V) to vanadium(II) by zinc and acid, gives a very characteristic test for vanadium. Addition of a few drops of hydrogen peroxide to a vanadate V) gives a red colour (formation of a peroxo-complex) (cf. titanium, which gives an orange-yellow colour). 

Copperil) oxide, CujO, occurs naturally as the red cuprite. It is obtained as an orange-yellow precipitate by the reduction of a copper(II) salt in alkaline solution by a mild reducing agent, for example glucose, hydroxylamine or sodium sulphite ... 

Physical Properties. All yellow or orange-yellow solids except... 

Dissolve I drop of quinoline in 1 ml. of dil. HCl and add a few drops of a saturated solution of potassium dichromate. A copious orange-yellow precipitate of quinoline dichromate, (C,H7N)2 HjCrj07, is formed pyridine does not give a crystalline dichromate under these conditions. 

Formation of methyl-orange cf. p. 214). Dissolve about 0 3 g. of sul-phanilic acid in 2 ml. of 10% aqueous NajCOj solution. Cool m ice-water and add 2 to 3 drops of 20% NaNOj solution. Now add about I ml. of cold dil. HCl, shake and leave for 2-3 minutes. Meanwhile dissolve i drop of dimethylaniline in a few drops of dil. HCl, cool thoroughly in ice-water and then add to the cold diazo solution. Shake well and make alkaline with aqueous NaOH solution note the formation of a deep orange-yellow coloration or precipitate. On the addition of HCl, a bright red coloration is produced. 

K. Treat with 2,4-dinitrophenylhydrazine reagent (pp. 263, 334). Yellow or orange-yellow precipitates given by most aldehydes and ketones. 

Cadmium hydroxide is the anode material of Ag—Cd and Ni—Cd rechargeable storage batteries (see Batteries, secondary cells). Cadmium sulfide, selenide, and especially teUuride find utiUty in solar cells (see Solarenergy). Cadmium sulfide, Hthopone, and sulfoselenide are used as colorants (orange, yellow, red) for plastics, glass, glazes, mbber, and fireworks (see Colorants for ceramics Colorants forplastics Pigments). 

Color from Incandescence. Any object emits light when heated, with the sequence of blackbody colors, black, red, orange, yellow, white, and bluish-white as the temperature increases. The locus of this sequence is shown on a chromaticity diagram in Eigure 14. 

Cadmium sulfide yellow can be considered for the brightest low temperature apphcations (15). It is a very bright, clean orange yellow. Primrose yellow and light yellow shades are made by precipitating small amounts of ZnS with the CdS. All the limitations of the cadmium sulfoselenide reds discussed above apply to the cadmium sulfide yellow. 

It was separated five pigments = 0.08 (orange - yellow zone),... 

The triphenylmethoxyacetate was prepared in 53% yield from a nucleoside and the sodium acetate (Ph3C0CH2C02Na, i-Pr3C6H2S02Cl, Pyr) as a derivative that could be easily detected on TLC (i.e., it has a distinct orange-yellow color after it is sprayed with ceric sulfate). It is readily cleaved by NH3/MeOH (100% yield). ... 

Ferrocene-1,1 -dicarhoxylic acid [1293-87-4] M 274.1, m >250°(dec), >300°. Orange-yellow crystals from AcOH. Sublimes above 230°. Monomethyl ester m 147-149° [Dokl Acad Nauk USSSR 115, 518 1957]. Dimethyl ester m 114-115° [J Am Chem Soc 14, 3458 1958]. Diacid chloride m 92-93° from pet ether. [Dokl Acad Nauk SSSR 120 1267 1958 127 333 7959.]... 

The solution at this point should be clear, but it may acquire a rather pronounced orange-yellow color when viewed in bulk. It should not, however, turn purple. 

Erom a run of live times the scale described, the submitters obtained 219 g. (71%) of an orange-yellow crystalline product, m.]). 88 90°. 

B. 3-Hydroxycinchoninic acid. A 3-1., four-necked flask (Note 1) is equipped with a sealed mechanical stirrer, gas inlet tube, gas outlet consisting of a 1-mm. capillary (Note 7), and thermometer. The flask is charged with a freshly prepared solution containing 448 g. (8 moles) of reagent grade (85% minimum assay) potassium hydroxide and 900 ml. of water. The solution (hot from dissolution of potassium hydroxide) is stirred and 147 g. (1 mole) of isatin (Note 8) is introduced. The solid quickly dissolves to give an orange-yellow solution. 

Bromine is a dark red volatile liquid with a pungent odour. The vapour attaeks the eyes and mueous memhranes. It eomhines spontaneously and with deflagration with phosphorus, arsenie and potassium and with many other elements when warmed. It hleaehes litmus and turns stareh paper orange/yellow. 

Aluminium chloride (anhydrous) AICI3 Orange, yellow, grey or white powder which is a severe respiratory irritant and can cause skin/eye burns Reacts with air moisture to form corrosive HCI gas Violent reaction when a stream of water hits a large amount Do not use water in vicinity... 

Chemical Designations - Synortyms Ammonium Bichromate Chemical Formula (NH4)2Cr20,. Observable Characteristics - Physical Stale (as normally shipped) Solid Color Orange-yellow bright red-orange orange to red Odor None. 

Substances containing aldehyde or keto groups yield yellow to orange-yellow chromatogram zones on an almost colorless background [1,11]. Silymarin appears red-blue and silydianine ochre-colored [9]. 

Nitroindole (ARf 40—45), 5-chloroindole (jiRf 60 — 65) and indole QiRf 70—75) yielded orange-yellow chromatogram zones on a pale yellow background. If the chromatogram was exposed to ammonia vapor for 15 s the color was intensified. The detection limits were 10 ng substance per chromatogram zone. 

---