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The reagents consist of resorcinol and concentrated hydrochloric acid: The acid hydrolysis of polysaccharide and oligosaccharide ketoses yields simpler sugars followed by furfural. [1] The dehydrated ketose then reacts with two equivalents of resorcinol in a series of condensation reactions to produce a molecule with a deep cherry red color.
Small amounts of hydrogen chloride for laboratory use can be generated in an HCl generator by dehydrating hydrochloric acid with either sulfuric acid or anhydrous calcium chloride. Alternatively, HCl can be generated by the reaction of sulfuric acid with sodium chloride: [17] NaCl + H 2 SO 4 → NaHSO 4 + HCl↑. This reaction occurs at room ...
Hydrochloric acid is a strong inorganic acid that is used in many industrial processes such as refining metal. The application often determines the required product quality. [25] Hydrogen chloride, not hydrochloric acid, is used more widely in industrial organic chemistry, e.g. for vinyl chloride and dichloroethane. [8]
[4] Column J is the color scheme used by the molecular visualizer Jmol. [9] Column R is the scheme used by Rasmol; when two colors are shown, the second one is valid for versions 2.7.3 and later. [9] [10] Column P consists of the colors in the PubChem database managed by the United States National Institute of Health.
Bial's reagent consists of 0.4 g orcinol, 200 ml of concentrated hydrochloric acid and 0.5 ml of a 10% solution of ferric chloride. [2] Bial's test is used to distinguish pentoses from hexoses; this distinction is based on the color that develops in the presence of orcinol and iron (III) chloride. Furfural from pentoses gives a blue or green color.
As such, the group reagent to separate them is hydrochloric acid, usually used at a concentration of 1–2 M. Concentrated HCl must not be used, because it forms a soluble complex ([PbCl 4] 2−) with Pb 2+. Consequently, the Pb 2+ ion would go undetected. The most important cations in the 1st group are Ag +, Hg 2+ 2, and Pb 2+.
The color of chemicals is a physical property of chemicals that in most cases comes from the excitation of electrons due to an absorption of energy performed by the chemical. The study of chemical structure by means of energy absorption and release is generally referred to as spectroscopy .
A flame test involves introducing a sample of the element or compound to a hot, non-luminous flame and observing the color of the flame that results. [4] The compound can be made into a paste with concentrated hydrochloric acid, as metal halides, being volatile, give better results. [5] Different flames can be tried to verify the accuracy of ...