121. Solving a chemistry problem

Determine the molar mass and aggregation number of sodium glycodeoxycholate micelles (one of the components of bile salts responsible for food digestion; molecular weight 471.6 g/mol) using the data of equilibrium centrifugation. The data include: temperature 20 °C, solvent density (0.5 mol/l NaCl) 1.0186 g/cm3, specific partial volume of micelles 0.77 cm3/g, angular velocity 1361 s-1. The design of the centrifuge made it possible to measure the concentration gradient Δc/Δх and the concentration at a certain distance x from the rotation axis. At x = 6.1972 cm c = 0.07797 g/dl and dc/dx = 0.2666 (g/dl)/cm were determined. (Note that concentration units are irrelevant for the solution).