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.

Kinetic evidence of a common mechanism in the oxidations of diethyl sulfide by dichromates and halochromates of heterocyclic bases

Abstract: The oxidations of diethyl sulfide by potassium dichromate, pyridinium dichromate, quinolinium dichromate, imidazolium dichromate, nicotinium dichromate, isonicotinium dichromate, pyridinium fluorochromate, quinolinium fluorochromate, imidazolium fluorochromate, pyridinium chlorochromate, quinolinium chlorochromate, and pyridinium bromochromate follow identical kinetic orders—first-order each with respect to the chromium(VI) reagents, sulfide and hydrogen ion, and moderately inhibited by manganese(II) ion. The energy of activation varies linearly with the logarithm of frequency factor and so does the enthalpy of activation with the entropy of activation. Also, the activation free energies do not differ significantly. The dichromates and halochromates of heterocyclic bases oxidize diethyl sulfide via a common mechanism. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 35: 1–8, 2003

Abschwächung der ekzematogenen Wirkung des Zementes durch Ferrosulfat

Abstract: Ferrous Sulphate combines with Potassium Dichromate in cement to form an insoluble compound. The addition of 0.3% Ferrous Sulphate to patch tests with cement reduced in sensitive individuals the intensity of patch test reactions and abolished it in some altogether. Patients with a normal skin alkaline resistance test benefitted most. These observations suggest possibilities of preventing cement-induced Chromate sensitivity.

Modified APHA closed-tube reflux colorimetric method for TOC determination in water and wastewater.

Abstract: The analysis of total organic carbon (TOC) by the American Public Health Association (APHA) closed-tube reflux colorimetric method requires potassium dichromate (K2Cr2O7), silver sulfate (AgSO4), and mercury (HgSO4) sulfate in addition to large volumes of both reagents and samples. The method relies on the release of oxygen from dichromate on heating which is consumed by carbon associated with organic compounds. The method risks environmental pollution by discharging large amounts of chromium (VI) and silver and mercury sulfates. The present method used potassium monochromate (K2CrO4) to generate the K2Cr2O7 on demand in the first phase. In addition, miniaturizing the procedure to semi microanalysis decreased the consumption of reagents and samples. In the second phase, mercury sulfate was eliminated as part of the digestion mixture through the introduction of sodium bismuthate (NaBiO3) for the removal of chlorides from the sample. The modified method, the potassium monochromate closed-tube colorimetry with sodium bismuthate chloride removal (KMCC-Bi), generates the potassium dichromate on demand and eliminates mercury sulfate. The semi microanalysis procedure leads to a 60% reduction in sample volume and ≈ 33.33 and 60% reduction in monochromate and silver sulfate consumption respectively. The LOD and LOQ were 10.17 and 33.90 mg L−1 for APHA, and 4.95 and 16.95 mg L−1 for KMCC-Bi. Recovery was between 83 to 98% APHA and 92 to 104% KMCC-Bi, while the RSD (%) ranged between 0.8 to 5.0% APHA and 0.00 to 0.62% KMCC-Bi. The method was applied for the UV-Vis spectrometry determination of COD in water and wastewater. Statistics was done by MINITAB 17 or MS Excel 2016.

[Skin reactivity in subjects sensitive to different concentrations of nickel, chromium and cobalt].

Abstract: Patch tests with serial dilutions of nickel sulphate, potassium dichromate and cobalt chloride in petrolatum were performed on 124 nickel-sensitive, 64 chromium-sensitive, and 72 cobalt-sensitive subjects. The lowest eliciting patch test concentrations were as follows: nickel sulphate--0.005, potassium dichromate--0.0025, and cobalt chloride--0.005.