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Conductometric Studies of Copper (II) Soap in Benzene Methanol at Various Temperatures

Rashmi Sharma, L. C. Heda, Renu Bhutra and K. G. Ojha

The critical micelle concentration and conductivity behaviour of copper (II) soap solution in benzene-methanol mixtures have been determined by the following equation at various temperatures (40, 45, 50 and 550C): log μ = A + B log c Where A and B are constants, c is concentration of copper soap in g.moles/litre and μ is molecular conductivity. The values of log μ and B generally increase with temperature. Both the values of log μ and B also increase with increase in the volume percent of methanol in the system. The above system obeys the Krauss and Bray type expression and data show that in general, dissociation constant increases and limiting molar conductance decreases with the temperature upto 50% methanol in the solvent mixture. The work has been extended to collect thermodynamic parameters such as the heat of dissociation, H0, to enable the behaviour of soap solutions to be better understood. In regard to chain length of the soap, the cmc values are in the order: Caprate < Caprylate. CMC increases with the increase in the methanol percent in the solvent mixture. The results confirm that the change in the nature of micelles from hydrophilic oleomicelles to lipophilic hydromicelles occurs in solutions at about 50% methanol.