Journal of Thermal Analysis and Calorimetry

, Volume 75, Issue 3, pp 815-836

First online:

New Physico-Chemical Properties of Extremely Diluted Aqueous Solutions

  • V. EliaAffiliated withDepartment of Chemistry, University 'Federico II' of Naples, Complesso Universitario di Monte S. Angelo Email author 
  • , M. NiccoliAffiliated withDepartment of Chemistry, University 'Federico II' of Naples, Complesso Universitario di Monte S. Angelo

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The extremely diluted solutions are anomalous solutions obtained through the iteration of two processes: a dilution 1:100 in mass and a succussion. The iteration is repeated until extreme dilutions are reached (less than 1·10-5mol kg-1) to the point that we may call the resulting solution an extremely diluted solution, namely the composition of the solution is identical to that of the solvent used (e.g. twice distilled water). We conducted thermodynamic and transport measurements of the solutions and of the interaction of those solutions with acids or bases. The purpose of this study is to obtain information about the influence of successive dilutions and succussions on the water structure of the solutions under study. We measured the heats of mixing of acid or basic solutions with such extremely diluted solutions, their electrical conductivity and pH, comparing with the analogous heats of mixing, electrical conductivity and pH of the solvent. We found some relevant exothermic excess heats of mixing, higher electrical conductivity and pH than those of the untreated solvent. The measurements show a good correlation between independent physico-chemical parameters. Care was taken to take into account the effect of chemical impurities deriving from the glass containers. Here we thus show that successive dilutions and succussions can permanently alter the physico-chemical properties of the water solvent. The nature of the phenomena here described still remains unexplained, nevertheless some significant experimental results were obtained.

solute-solvent interaction calorimetry pH sulutions conductivity aqueous solution