ISO 1691:1976
ISO 1691:1976



Three cases, defined by a preliminary test, are envisaged: silicates containing neither sulphides nor chlorates; silicates containing sulphides; silicates containing chlorates. The method based on boiling of an acidified test portion containing methyl orange and with a lead paper strip in the vapour. The presence of sulphides produces blackening of the paper and the presence of chlorates decolorizes the methyl orange. Volumetric*measurement of carbon dioxide evolved from silicates containing neither sulphides nor chlorates by reaction with a hydrochloric acid solution. The principle for the oxidation of sulphides and the reduction of chlorates are specified.

General information 

  •  : Published
     : 1976-07
  •  : 1
     : 5
  •  : ISO/TC 47 Chemistry
  •  :
    71.060.50 Salts

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