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The hydrogen chromate ion may be protonated, with the formation of molecular chromic acid, H 2 CrO 4, but the pK a for the equilibrium H 2 CrO 4 ⇌ HCrO − 4 + H + is not well characterized. Reported values vary between about −0.8 and 1.6. [4] The dichromate ion is a somewhat weaker base than the chromate ion: [5]
Chromate and dichromate have equal concentrations. Setting [CrO 2− 4] equal to [Cr 2 O 2− 7] in Eq. 3 gives [CrO 2− 4] = 1 / β 2 [H +] 2 . The predominance diagram is interpreted as follows. The chromate ion is the predominant species in the region to the right of the green and blue lines. Above pH ~6.75 it is always the ...
Cadmium chromate; Caesium chromate; Calcium chromate; Chromate ester; Chromated copper arsenate; Template:Chromates and dichromates; Chrome orange; Chrome yellow; Chromic acid; Chromium(VI) oxide peroxide
In 2005–06, potassium dichromate was the 11th-most-prevalent allergen in patch tests (4.8%). [12] Potassium dichromate is one of the most common causes of chromium dermatitis; [13] chromium is highly likely to induce sensitization leading to dermatitis, especially of the hand and forearms, which is chronic and difficult to treat ...
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Chromate conversion coating or alodine coating is a type of conversion coating used to passivate steel, aluminium, zinc, cadmium, copper, silver, titanium, magnesium, and tin alloys. [ 1 ] : p.1265 [ 2 ] The coating serves as a corrosion inhibitor , as a primer to improve the adherence of paints and adhesives , [ 2 ] as a decorative finish, or ...
Chromyl chloride can be prepared by the reaction of potassium chromate or potassium dichromate with hydrogen chloride in the presence of sulfuric acid, followed by distillation. [3] [4] K 2 Cr 2 O 7 + 6 HCl → 2 CrO 2 Cl 2 + 2 KCl + 3 H 2 O. The sulfuric acid serves as the dehydration agent.
A chromate ester is a chemical structure that contains a chromium atom (symbol Cr) in a +6 oxidation state that is connected via an oxygen (O) linkage to a carbon (C) atom. The Cr itself is in its chromate form, with several oxygens attached, and the Cr–O–C attachment makes this chemical group structurally similar to other ester functional groups.