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A Spectrophotometric Study on Complex Formation of Nickel (II) and Cobalt (II) with Bromopyrogallol Red
Author(s) -
Dhupar S. C.,
Srivastava K. C.,
Banerji Samir K.
Publication year - 1972
Publication title -
journal of the chinese chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.329
H-Index - 45
eISSN - 2192-6549
pISSN - 0009-4536
DOI - 10.1002/jccs.197200028
Subject(s) - chemistry , nickel , cobalt , enthalpy , metal ions in aqueous solution , metal , ion , stability constants of complexes , gibbs free energy , nuclear chemistry , inorganic chemistry , analytical chemistry (journal) , chromatography , thermodynamics , organic chemistry , physics
Nickel (II) and Cobalt (II) form in 50% ethanolic medium, a bluish violet complex with Bromopyrogallol Red (BPR) in the mole ratio of 1:1 (Ni(II)) and 1:2 (Co(II)), both having at 620 nm , stable in the p H ranges 6.0‐7.5 and 5.5‐7.0, respectively. The thermodynamic stability constants and overall changes in the free energy of formation, enthalpy and entropy have been determined in both the cases. Beer's law is obeyed over the concentration range 0.5‐5.0 ppm of Nickel and 0.2‐3.0 ppm of Cobalt at 620 nm . The net molar absorptivities are 1.6 × 10 4 and 2.9 × 10 4 and the sensitivities are 0.00367 and 0.00219 μ g of Nickel and Cobalt per cm ,/ 2 . The effect of diverse ions on the metal ions determination is also reported.