75. Solving a chemistry problem

502. Fats and lipids are absorbed by the body through a multi-stage dispersion process, in the last stages of which the ability of bile salts to form mixed micelles plays an important role. Micelles of one of the components of such salts, the sodium salt of deoxycholic acid (molar mass 415.55 g/mol), were studied by osmometry at 25°C in an aqueous solution of NaCl with the following results
cm, kg/m3 4.0 8.0 12.0 16.0
π, kPa (0.03 mol/L NaCl solution) 1.47 3.18 5.15 7.32
Cm - excess concentration of micelles in the solution chamber (relative to the solvent chamber)
Calculate from these data the molar mass of micelles and the number of molecules in a micelle (aggregation number).