Cadmium sulphide, formation

McCann JE, SkyUas Kazacos M (1981) The Electrochemical deposition and formation of cadmium sulphide thin film electrodes in aqueous electrolytes. J Electroanal Chem 119 409-412... 

Parhutik VP, Makushok IE, Kudriavtsev E, Sokol VA, Khodan AN (1987) An X-ray electronic study of the formation of anodic oxide films on aluminium in nitric acid. Electrochemistry (Elektrokhymia) 23 1538-1544 Kundu M, Khosravi AA, Kulkami SK (1997) Synthesis and study of organically capped ultra small clusters of cadmium sulphide. J Mater Sci 32 245-258... 

This consists of cadmium sulphide and, according to the conditions of its formation, exhibits various colours from pale lemon yellow to deep yellow and orange. 

Towey, T. R, Khan-Lodhi, A., and Robinson, B. H. (1990). Kinetics and mechanism of formation of quantum-sized cadmium sulphide particles in water-aerosol-OT-oil microemulsions. J Chem Soc Faraday Trans 86, 3757-3762. 

Pass the solution through the column at a rate of 5 ml/min, and then wash the column with 50 ml of hot water to remove the mineral acid. Check the completeness of absorption of tbe copper and cadmium ions. For tbis purpose, pour 3-5 ml of the washing water into a test tube and add a solution of ammonium sulphide or hydrogen-sulphide water to it. The formation of a precipitate indicates incomplete absorption, which occurs only if there is an error in performing the operations described above. In this case, the experiment has to be repeated. To do tbis, wash the column with a solution of hydrochloric acid (1 3), next with water until the washing solution has a neutral reaction, and then pass the solution through the column again. 

Procedure. Boil the fibre in 30 per cent sulphuric acid and trap the carbon disulphide set free in a U-tube (Fig. 40) filled with a 1 per cent ethanolic solution of diethylamine. Trap the hydrogen sulphide in a tube containing cadmium acetate solution, incorporated between the sulphuric acid and sample and the trapping U-tube. Determine the diethyldithiocarbamate formed polarographically, using the anodic wave of the mercury salt formation, as in the determination of carbon disulphide given in Chapter VI. 

In comparison with the acid digestion method, the hydrogenation method is more susceptible to matrix interferences. Two types of interferences are possible. Samples containing zinc, cadmium or mercury cannot be analyzed, as the high volatility of these elements results in the formation of a metallic mirror on the cooler parts of the tubing, which partially or completely absorbs the released sulphide. Sulphur may also be retained in the sample because it is present in the form of sulphur compounds which are not reduced or decomposed, e.g. manganese sulphide, or is held in crystal lattices which do not allow sufficiently rapid diffusion of sulphur at the temperature of 1150°C. 

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