27. Solving a chemistry problem

3. During the adsorption of acetic acid by non-porous soot, the following data were obtained:
r, Pa 15.0 33.0 78.0 171,
a, mol/kg 9.5 16.5 21.5 27.5
(p is the equilibrium vapor pressure, and is the amount of adsorption)
The isotherm is described by the Langmuir equation. Calculate the area occupied by an acetic acid molecule in a dense monolayer if the specific surface area of non-porous carbon black is 74.5 m2/kg.