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The sample is dissolved in water, or a mixture of water and ethanol, and a few drops of neutral ferric chloride (FeCl 3) solution, which is prepared by adding de-ionised water. Add sodium hydroxide to the mixture until a permanent brown precipitate is formed. The formation of a red, blue, green, or purple coloration indicates the presence of ...
The affinity of iron(III) for oxygen ligands was the basis of qualitative tests for phenols. Although superseded by spectroscopic methods, the ferric chloride test is a traditional colorimetric test. [26] The affinity of iron(III) for phenols is exploited in the Trinder spot test. [27]
Total phenols (or antioxidant effect) can be measured using the Folin-Ciocalteu reaction. Results are typically expressed as gallic acid equivalents (GAE). Ferric chloride (FeCl 3) test is also a colorimetric assay. Lamaison and Carnet have designed a test for the determination of the total flavonoid content of a sample (AlCI 3 method). After ...
In chemistry, iron(III) or ferric refers to the element iron in its +3 oxidation state. Ferric chloride is an alternative name for iron(III) chloride (FeCl 3). The adjective ferrous is used instead for iron(II) salts, containing the cation Fe 2+. The word ferric is derived from the Latin word ferrum, meaning "iron".
For example, in the ferric chloride test, used to determine the presence of phenols, iron(III) chloride reacts with a phenol to form a deep violet complex: [71] 3 ArOH + FeCl 3 → Fe(OAr) 3 + 3 HCl (Ar = aryl)
The free radicals generated by this process engage in secondary reactions. For example, the hydroxyl is a powerful, non-selective oxidant. [6] Oxidation of an organic compound by Fenton's reagent is rapid and exothermic and results in the oxidation of contaminants to primarily carbon dioxide and water.
Hydrated forms of ferrous chloride are generated by treatment of wastes from steel production with hydrochloric acid. Such solutions are designated "spent acid," or "pickle liquor" especially when the hydrochloric acid is not completely consumed: Fe + 2 HCl → FeCl 2 + H 2. The production of ferric chloride involves the use of ferrous chloride.
Ferric chloride gives a bluish-violet coloration with the aqueous solution. Unlike resorcinol it does not give a fluorescein with phthalic anhydride . Oxidation of the ammoniacal solution gives orcein , C 28 H 24 N 2 O 7 , the chief constituent of the natural dye archil .