112. Solving a chemistry problem

For the adsorption of ethyl chloride by charcoal as a function of pressure at 0 degrees, the following data were obtained
P mmHg 20 50 100 200 300
m, city 3.0 3.8 4.3 4.7 4.8
P is the vapor pressure of ethyl chloride, m is the mass of adsorbed vapor.
Within the framework of the Langmuir theory, determine a) the proportion of adsorption sites on the adsorbent surface occupied by the adsorbate at each of these pressures, b) the surface area of the adsorbent sample