Which substance is used as an adsorbent in chromatography?

Adsorption is a phenomenon in which a substance

Which of the following is true for the adsorption of a gas on the surface of a solid?

Plot of $\log \left( \frac{x}{m} \right)$ against $\log P$ is a straight line inclined at an angle of $45^o$. When the pressure is $0.5 \ atm$ and Freundlich parameter,$k$ is $10$,the amount of solute adsorbed per gram of adsorbent will be ...... $g$ $(\log 5 = 0.6990)$

Match List-$I$ with List-$II$.

List-$I$	List-$II$
$A$. Physisorption	$I$. Single layer adsorption
$B$. Chemisorption	$II$. $20-40 \, kJ \, mol^{-1}$
$C$. $N_{2(g)} + 3H_{2(g)} \xrightarrow{Fe(s)} 2NH_{3(g)}$	$III$. Chromatography
$D$. Analytical Application of Adsorption	$IV$. Heterogeneous catalysis

Choose the correct answer from the options given below:

The decomposition of phosphine $(PH_3)$ on tungsten at low pressure is a first-order reaction. It is because the