84. Solving a chemistry problem

102. According to the results of measurements of the surface tension of solutions of n-butyl alcohol in water at 12.0 ° C, depending on the concentration (table below, concentration C in mmol / l, surface tension b in mN / m), find the limiting adsorption of alcohol G∞ by the graphical method, and calculate the area occupied by 1 alcohol molecule in a saturated adsorption layer assuming monomolecular adsorption.

С 0 3.2 4.8 6.4 8.5 13.0 16.9 26.0 33.8 51.0 67.5 102 135 203
b 74.2 73.0 73.1 72.0 71.3 71.3 70.1 68.0 65.8 63.1 60.7 56.9 53.8 48.9