NEW SPECTROPHOTOMETRIC METHOD WITH KMnO4 FOR DETERMINATION OF HYPOCHLORITE IN COMMERCIAL BLEACHES

  • P. Gengan Department of Chemistry, University of Durban-Westville, Durban 4000, South Africa
  • S. B. Jonnalagadda* Department of Chemistry, University of Durban-Westville, Durban 4000, South Africa
Keywords: Commercial bleaches, Hypochlorite determination, Spectrophotometric method

Abstract

Hypochlorite with a strong germicidal and bleaching action forms the active component in most commercial bleaches. The new method, an instrument-based and simple experimental procedure involves the reaction of the hypochlorite with arsenious oxide (As2O3) (pH 6.5) followed by the coupled reaction of residual As2O3 with permanganate at acidic pH. A titration procedure is described and spectrophotometric method is designed using four ranges of calibration curves to enable the determination of hypochlorite in the range 2.5 x 10-4 to 2.4 x 10-2 M from the KMnO4 absorbance measurements. A series of commercial bleaches are tested using the proposed spectrophotometric method. The results proved more precise and accurate than by arsenite method.

KEY WORDS: Commercial bleaches, Hypochlorite determination, Spectrophotometric method

Bull. Chem. Soc. Ethiop. 2005, 19(1), 1-8.
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Articles

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eISSN: 1726-801X
print ISSN: 1011-3924