Chloride salts qualitative analysis

The inorganic compounds in Table 1 include arsenic compounds, cadmium sa1ts lead chloride, lead nitrate, and mercury salts. These are highly poisonous compounds as well as being suspected teratogens, and they need to be handled with extra care. Fortunately, most of these substances are used only in dilute solution and usually in semi-micro quantities. Solutions of arsenic, cadmium, lead, and mercury salts are typically used in connection with Qualitative Analysis procedures, and the amounts used are often no more than a few drops. Hand washing at the end of the laboratory period is especially important after working with solutions such as these. 

Excitation of the outer ns electron of the M atom occurs easily and emission spectra are readily observed. We have aheady described the use of the sodium D-line in the emission spectrum of atomic Na for specific rotation measurements (see Section 3.8). When the salt of an alkali metal is treated with concentrated HCl (giving a volatile metal chloride) and is heated strongly in the non-luminous Bunsen flame, a characteristic flame colour is observed (Li, crimson Na, yellow K, lilac Rb, red-violet Cs, blue) and this flame test is used in qualitative analysis to identify the M ion. In quantitative analysis, use is made of the characteristic atomic spectrum in flame photometry or atomic absorption spectroscopy. 

The procedures and principles of qualitative analysis are covered in many introductory chemistry laboratory courses. In qualitative analysis, students learn to analyze mixtures of the common positive and negative ions, separating and confirming the presence of the particular ions in the mixture. One of the first steps in such an analysis is to treat the mixture with hydrochloric acid, which precipitates and removes silver ion, lead(II) ion, and mercury(I) ion from the aqueous mixture as the insoluble chloride salts. Write balanced net ionic equations for the precipitation reactions of these three cations with chloride ion. 

Thorough characterization of commercial products requires determination of the anion associated with the cationic surfactant as well as determination of other salts present. Determination of chloride and sulfate ions is described in Chapter 1. These and other anions are usually determined by ion chromatography, although wet chemical methods may also be applied after qualitative analysis has shown which ions are present. 

Cyclotrimethylenetrinitrosainine (R-Salt), Analytical Procedures No information is available as to the detection, identification or analysis of R-Salt either alone or in the presence of other expls. However, it is believed that R-Salt can be detected qualitatively by the. tests for N-nitros-amines given by Feigl (Ref 1) and quantitatively by the chromous chloride method given by Jamison (Ref 2) and Gutmacher e.t al (Ref 3)... 

TiCU is produced by the reduction of the tetrachloride with hydrogen or a metal like silver or mercury. When heated in the air it breaks up, giving the volatile tetrachloride and the solid dichloride. TiCl is deli quescent, forms a reddish violet solution with water, and violet crystals, TiCU 6 H20, from a hydrochloric acid solution. An unstable green hydrate of the same composition is formed when an aqueous solution of the trichloride is covered with ether and saturated at 0° with HC1. From the violet form all the chlorine may be removed by AgNO , but this is probably not true of the green modification. The trichlorides of chromium and vanadium likewise are known in two forms. TiCla forms double salts with the chlorides of rubidium and caesium. It is a more powerful reducing agent than stannous chloride and on this account finds extensive application in both qualitative and quantitative analysis. 

The infrared spectra of many inorganic salts have been determined in the sodium chloride region [ ] and in the cesium bromide region [ ]. From these studies, several characteristic frequencies for polyatomic ions have been found. These frequencies have proved useful in qualitative inorganic analysis. 

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