93. Solving a chemistry problem

113. Find the limiting adsorption G∞ by the graphical method, and calculate the area occupied by 1 molecule in a saturated monomolecular layer, according to the following data on the adsorption of n-butyl alcohol from an aqueous solution at 39.0 ° C (C concentration in mmol / l, surface tension σ in mN/m):
С 0 4.8 8.5 16.9 26.0 33.8 51.0 67.5 102 135 203 270 406
σ 70.1 69.2 67.6 67.0 64.3 62.5 61.1 57.5 53.5 50.3 45.2 41.3 35.4