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  • 1 Atomic Energy Establishment Cairo (Egypt)
  • 2 Aswan University Chemistry Department Aswan (Egypt)
  • 3 Kuwait University Chemistry Dept. Kuwait
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Abstract  

The effect of temperature on the extraction of Co2+, Zn2+, Cd1+ and Hg2+ by salicylaldoxime diluted with carbon tetrachloride was investigated radiometrically. It is found that the extraction constants at 25°C increase linearly with l/r, where r is the effective coordination radius of the metal cation. The thermodynamic data calculated from the effect of temperature on the extraction showed that, 1) the extraction process is endothermic, 2) the dehydration of the metal cation in the extraction process is the predominating factor in determining the enthalpy variation and 3) the entropy variation is a contribution of the degree of order caused by the hydration of the proton and the highly ordered chelate structure of the extracted species.