Potassium dichromate

About: Potassium dichromate is a research topic. Over the lifetime, 1430 publications have been published within this topic receiving 18967 citations. The topic is also known as: Potassium dichromate(VI) & Chromium potassium oxide.

Synthesis and crystal structures of two new uranyl coordination compounds obtained in aqueous solutions of 1-butyl-2,3-dimethylimidazolium chloride

Abstract: Two new uranyl coordination compounds, [C9H17N2]3[(UO2)2(CrO4)2Cl2(H2O)2]Cl·5H2O (1) and (C9H17N2)[(UO2)(C2O4)Cl] (2), have been synthesized by adding potassium dichromate (K2Cr2O7) or oxal...

Analysis of Potassium Dichromate Method for Determining COD in Water

Abstract: The potassium dichromate method is the national standard method for determining COD in the industrial wastewater.Based on massive experiments,accuracy,recovery of the method,standard solution's stability and the sampling method are discussed in this paper.The problems in the practical work are analyzed.The effective adjustment and control methods are adopted to reduce errors and to ensure reality of the determined water sample.

Surface area determination of magnesium powder with chromium‐51 tracer solutions

Abstract: A study has been made of the adsorption of 51Cr, from aqueous solutions of labelled potassium dichromate, on to coarse magnesium powder at room temperature. The measurement of the rate of uptake of 51Cr on the powder and comparison with a magnesium standard of known area has led to a simple method for the determination of the surface area of the powder.

Oxidation products of fused 2-hetarylimidazole derivatives

Abstract: Oxidation of 5-(1-methyl-1H-benzimidazol-2-yl)thiophene-, and -selenophene-2-carbaldehydes with potassium dichromate in 20% aqueous sulfuric acid afforded the corresponding carboxylic acids. Analogous reaction with 5-(1-methyl-1H-benzimidazol-2-yl)furan-2-carbaldehyde led to the formation of 1-methyl-1H-benzimidazole as a result of decarboxylation of the primary oxidation product and subsequent decomposition of the furan ring. Probable factors responsible for instability of 5-(1H-benzimidazol-2-yl)-hetarene-2-carboxylic acids were considered. The oxidation of 2-furylnaphtho[2,3-d]- and 2-hetarylphenanthro-[9,10-d]imidazoles gave, respectively, an anthraquinone analog and 6,7-quinones. π-Electron-rich heterocycles in 2-furyl- and 2-pyrrolylphenanthro[9,10-d]imidazoles were oxidized completely, being replaced by hydrogen.

Oxidative coloring of human hair uses freshly prepared mixture of oxidation dye composition containing metal salt and/or hydroquinone, more alkaline oxidation dye composition and acidic hydrogen peroxide

Abstract: In oxidative coloring of human hair, composition A, with pH \} 9, contains oxidation dye precursor(s) (I) and metal salt(s) and/or hydroquinone is mixed, immediately before application, with a composition B, containing (I) and alkali to increase the pH \> 9 and with an acidic hydrogen peroxide composition, giving a mixture with pH 8-10.5; applied to the hair; and washed off after 5-50 minutes. In oxidative coloring of human hair, composition A contains oxidation dye precursor(s) (I) and 0.0005-1 wt.% compound(s) selected from alkali iodides, manganese dioxide, lithium chloride, potassium dichromate, magnesium acetate, calcium chloride, barium nitrate, copper (II) chloride, copper(II) sulfate, iron chloride, cerium sulfate, vanadium sulfate and/or hydroquinone. Immediately before application, composition A, with pH \} 9, is mixed with a composition B, containing (I) and enough alkali to increase the pH to over 9 and (then) with an acidic hydrogen peroxide composition, so that the mixture has pH 8-10.5. It is applied to the hair and washed off after about 5-50 minutes.