Interaction of Charcoal with Acidified Potassium Dichromate and Alkaline Potassium Ferricyanide

Inetractions of charcoals, coated with different amounts of carbon-oxygen surface complexes, with acidified potassium dichromate and alkaline potassium ferricyanide, have been studied. It has been found that charcoals associated with CO2-complex are far more efficient as reducing agents than those free of this complex or free of combined oxygen altogether. The oxygen rendered available during each interaction has been accounted for either as gaseous carbon dioxide, a product of combustion, or as CO2-surface complex, formed by chemisorption of oxygen. The chemisorption of oxygen by charcoal appears to be a preliminary step preceding combustion. The interaction with a stronger oxidising agent causes relatively more combustion and less chemisorption than that with a milder oxidising solution