143. Solving a chemistry problem

6.15. The amount of (V) methane (273 K and 1.01 * 105 Pa) adsorbed on 1 g of coal at 194.5 K and various pressures is as follows:
P * 10–3, Pa 25.6 36.7 47.8 60.5 77.0
V * 106, m3 / g 15.2 19.1 22.3 25.3 28.4
Build the adsorption isotherm V = f (P) and p / V = f (P); describe the adsorption isotherm using the Langmuir equation; determine the adsorption value (m3 / g) at maximum adsorbent filling; determine the degree of filling of the adsorbent at a pressure of 5 * 104 Pa; at what gas pressure the degree of filling is 0.4.