The molar volume, viscosity, specific viscosity, and fluidity of copper surfactant derived from various edible oils in methanol -benzene solvent have been determined at a constant temperature 303 K.

The results were used to calculate (CMC), soap complex-solvent interactions and the effect of chain length of the surfactant molecule on various parameters.

The conclusions with regard to soap-soap and soap- methanol -benzene interaction have been discussed in terms of well-known Moulik’s and Jones- Dole equations. The effect of surfactant concentration on viscosity of the solution in solvent mixture has been discussed.

The observations suggested that the structure breaking effect by the solute on the solvent molecules is more prominent above CMC as compared to below CMC after the formation of the micelles. The vital information plays an important role in various industrial process as well as biological applications.