126. Solving a chemistry problem

Using the data given for various options (Table 8):
1. Build a surface tension isotherm and find the surface activity of the substance on the graph.
2. Find the negative derivatives –db/dС for concentrations whose b values ​​do not lie on the tangent drawn to the initial section of the isotherm.
3. Having determined the negative derivatives –db/dС, calculate the Gibbs adsorption for these derivatives.
4. Calculate the S/G ratios for all values ​​of G and plot S/G versus S. Using the linear portion of the last plot, find the constant of the Langmuir equation.
5. Calculate the area occupied by an acid molecule in the surface layer S0.
Option 4
Solute Butyric acid
С•10–3 mol/m3 0 0.06 0.16 1.50 2.50 3.50 5.50
b•103 J/m2 71.96 70.28 67.75 49.64 42.35 37.07 29.51
V, J/m2 0.0194