143. Solving a chemistry problem

6.6. The amount of V nitrogen (273 K and 1.01 * 105 Pa) adsorbed on 1 g of coal at 273 K and various pressures is as follows:
P * 10–3, Pa 1.62 5.30 17.30 30.70 44.50
V * 106, m3 / kg 0.31 0.99 3.04 5.10 6.90
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 2 * 104 Pa; determine at what gas pressure the degree of filling of the adsorbent is 0.4.