Hydration potassium chromate

Materials Required Chloral hydrate 4.0 g sodium hydroxide (N) 30 ml sulphuric acid (N) phenolphthalein solution (1.0% w/v in 50% v/v alcohol) 0.1 N silver nitrate solution potassium chromate solution (5% w/v in water). [Pg.153]

Procedure Weigh accurately about 4 g of chloral hydrate and dissolve in 10 ml of DW and add 30 ml of N sodium hydroxide solution. Allow the resulting mixture to stand for 2 minutes, and then titrate with N sulphuric acid, employing phenolphthalein solution as indicator till a colour change from pink to colourless is achieved. Titrate the neutralized liquid thus obtained with 0.1 N silver nitrate using potassium chromate solution as indicator till precipitation of red chromate is obtained, Add, now 2/15th of the amount of 0.1 N silver nitrate used to the amount of N sulphuric acid used in the first titration and deduct the figure so obtained... [Pg.153]

Ammonium nitrate Ammonium perchlorate Barium chlorate (hydrate) Barium chromate Barium nitrate Barium peroxide Iron oxide Iron oxide Lead chromate Lead oxide (red lead) Lead peroxide Potassium chlorate Potassium nitrate Potassium perchlorate Sodium nitrate Strontium nitrate... [Pg.20]

Several types of corrosion inhibitors have been investigated in the last 20 years [53-55] these include calcium and sodium nitrites, sodium benzoate, sodium/potassium chromate, sodium salts of silicates and phosphates, stannous chloride, hydrazine hydrate, sodium fluorophosphate, permanganate, aniline and related compounds, alkalis, azides, ferrocyanide, EDTA and many chelating compounds. However, in terms of field practice and research data, nitrite-based compounds occupy a dominant position. [Pg.330]

Neutral solutions of cobalt salts produce with potassium chromate a reddish brown precipitate of hydrated basic cobalt chromate, Co0.CoGrO4.Aq. This reaction may be utilised in detecting small quantities of cobalt.4... [Pg.58]

No hydrates are formed under ordinary conditions. Observations on the solubility of potassium chromate were made by T. Thomson, A. Michel and... [Pg.128]

F. T. Frerichs observed no precipitation and F. Kuhlmann found that calcium carbonate is only partially converted into the chromate by a soln. of potassium chromate hme-water gives no precipitate with a soln. of potassium chromate. F. Mylius and J. von Wrochem obtained the anhydrous chromate by heating the hydrated salt—G. N. Wyroubofi said at 300°—or by warming a supersaturated soln., containing 15 to 20 per cent. CaCr04, over 36°. The yellow powder consists of fine needles. L. Bourgeois obtained crystals of the anhydrous chromate by melting a mixture of 2 eq. of calcium chloride with an eq. each of potassium and sodium chromates. D. Vorlander and H. Hempel observed no transformation into... [Pg.146]

Inorganic colorants listed in 21CFR 178.3297 include aluminum, aluminum hydrate, potassium silicate, aluminum silicate, barium sulfate, bentonite, calcium carbonate, calcium silicate, calcium sulfate, carbon black (channel process, prepared by the impingement process from stripped natural gas), chromium oxide green Cr203, cobalt aluminate (with restrictions), diatomaceous earth, iron oxides, kaolin (modified for use in olefin polymers in amounts up to 40%), magnesium oxides, magnesium silicate (talc), sienna, silica, titanium dioxide, titanium dioxide-barium sulfate, ultramarines, zinc carbonate (limited use), zinc chromate (less than 10%), zinc oxide (limited use), and zinc sulfide (less than 10%). [Pg.174]

Mercury perchloride and sodium hydrate give a yellow solution, also lead acetate and potasrium iodide or better still potassium chromate. [Pg.32]

For a Ydlow use (1) chloride of mercurj, and develop with sodium hydrate or caustic soda or (2) acetate of lead, and develop with potassium chromate or (3) dissolve equal parts of sulphate of copper and chloride of ammonia in water and develop by heat. The image disappears on cooling. [Pg.38]

According to the Colour Index (1971), this is copper chromate oxide hydrate (Cl 77403) with composition CuCrO4.2CuO.2H2O, produced by mixing aqueous potassium chromate and a copper salt. [Pg.97]

Zinc chromate hydroxide is one of two zinc chromates given by Kuhn and Curran (1986) as the composition of zinc yellow, the other being zinc potassium chromate hydrate (approximately K2O.4ZnCrO4.3H2O) (qq.v.). However, Leisy (1941) and Kittel (1960) suggest that examples of earlier pigments are more likely to composition based on the latter as zinc chromate hydroxide was only patented in 1941. [Pg.404]

Zinc chromates group Zinc potassium chromate hydrate Zinc yellow... [Pg.404]

Zinc chromates group Zinc oxides and hydroxides group Zinc sulfides group Aurichalcite Cadmium zinc sulfide Claraite Cobalt zinc oxide Copper zinc carbonate, rosasite type Franklinite Iron zinc oxide Iron zinc oxide Lead antimony zinc oxide Matraite Rosasite Smithsonite Sphalerite Wurtzite Zinc carbonate Zinc carbonate hydroxide Zinc dichromate hydrate Zinc hexacyanoferrate(II) Zinc oxide Zinc oxide sulfide Zinc phosphate Zinc potassium chromate Zinc potassium chromate hydrate Zinc sulfate Zinc sulfide Zinc sulfide hydrate Zinc titanate Zincite Blende Mosaic gold Murexide Bieganska et al. (1988) Merck Index (1996)... [Pg.405]

There are two formulations of zinc chromate which are termed zinc yellow - a zinc potassium chromate hydrate, with approximate... [Pg.408]

Zinc chromates group Chromium oxide Strontium chromate Zinc chromate hydroxide Zinc potassium chromate hydrate Chrome green Citron Yellow Permanent green Permanent yellow Ultramarine yellow Victoria green... [Pg.409]

Copper chromate oxide hydrate Cobalt chromate Iron dichromate Iron chromate hydroxide Manganese chromate hydrate Silver chromate Thallium chromate Titanium chromate Cadmium chromate Cadmium chromate hydroxide Mercury chromate Zinc dichromate hydrate Zinc chromate(VI) hydroxide Zinc sodium chromate Zinc potassium chromate... [Pg.422]

Solutions of the following salts are usually 0.5 M with respect to the hydrated salt ammonium thiocyanate, copper sulphate, iron(IIl) chloride, iron(II) sulphate, potassium iodide, potassium thiocyanate. Solutions of the following salts are usually 0.25 M barium chloride, calcium chloride, lead acetate, potassium chromate, potassium hexacyanoferrate(II), tin(II) chloride (with few pieces of Sn to stop aerial oxidation), zinc nitrate. [Pg.259]

Zinc yellow is a hydrated double salt of zinc and potassium chromate used principally in corrosion-inhibiting metal primers. It is becoming one ofthe few pigments permitted for use on steel connected in houses or apartments. The pigment is greenish yellow and offers poor opacity. [Pg.92]

To a solution of tetraethylenepentamine pentahydrochloride (tetren 5HC1, Aldrich) (2.24 g 6.0 mmol) dissolved in 20 mL of water is added 1.21 g of sodium hydroxide (30 mmol, 5 equiv). A solution of nickel(II) chloride hexa-hydrate in 10 mL of water (0.95 g, 4.0 mmol) is then slowly added. The mixture is stirred for 20 min before adding dropwise a solution of potassium hexacyano-chromate(lll) (0.325 g, 1 mmol) in a minimum of water. The solution is left... [Pg.147]

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