Which of the following can adsorb the largest volume of hydrogen gas?

The graph drawn between $\log \left(\frac{x}{m}\right)$ and $\log (p)$ is shown below with intercept $OA = 0.3010$. What is the value of $\left(\frac{x}{m}\right)$ at a pressure of $0.3 \ atm$ ? (Given: $\log 2 = 0.3010, \log 3 = 0.477$)

Froth floatation process for concentration of ores is an illustration of the practical application of:

How much vacuum is needed to obtain a clean surface of metal?

Which of the following statements about physical adsorption is not correct?

Which of the following statements is incorrect?