Composition and Stability of the Chelate between Aluminium (III) and sulpho-dichloro hydroxy-dimethyl fuchson dicarboxylic acid (trisodium salt) and analytical applications of the reaction

✍ Scribed by Suresh C. Srivastava; Surendra Nath Sinha; Arun K. Dey

• Book ID: 105350755
• Publisher: John Wiley and Sons
• Year: 1963
• Tongue: English
• Weight: 537 KB
• Volume: 20
• Category: Article
• ISSN: 1615-4150
• DOI: 10.1002/prac.19630200108

✦ Synopsis

Abstract

The reaction of sulpho‐dichloro hydroxy‐dimethyl fuchson dicarboxylic acid (trisodium salt) with aluminium (III) ions in aqueous solution to give a stable violet complex has been studied in detail, regarding the composition and stability of the chelate and its analytical applications. Absorbance as well as electrical conductance measurements have been performed to determine the composition of the chelate which comes out to be 1:1 (metal:chelating agent). The chelate has its maximum absorbance at 545 mμ, and is stable between pH 3.05 and 6.60. The system obeys Beer's Law over a concentration range of 0.013 to 0.980 p. p. m. of aluminium. The value of log K, as calculated by the absorbance data is 4.3 ± 0.1 at pH 4.0 ± 0.2, temperature 30°C and ionic strength 0.2 (KCl). The corresponding free energy change of formation has also been evaluated. The effects of pH, temperature, time and diverse ions on the reaction have been studied and suggestions have been advanced on the possible position of the chelate ring in the complex. A procedure for the colorimetric microdetermination of aluminium has also been suggested.