Draw a plot of variation in quantity of gas adsorbed x/m with the pressure of the gas. Plot also the graph between log x/m vs log p atconsttemp. What is the slope of this line?

An isotherm is a graph that is plotted between two variables keeping the temperature constant. Adsorption isotherm is a graphical representation of how the amount of gas adsorbed by the adsorbent varies with pressure at constant temperature. So when the variation of extent of adsorption with pressure is studied and the experimental data obtained is plotted, it is found that at high pressures, the amount of gas that can be adsorbed by the adsorbent becomes constant. That is, at high pressure, the extent of adsorption will not show any variation will pressure. In other word, it will become independent of pressure. This is why we obtain the following graph