Which of the following becomes less than zero during the process of adsorption?

The adsorbent used in adsorption chromatography is/are:
$A$. silica gel
$B$. alumina
$C$. quick lime
$D$. magnesia
Choose the most appropriate answer from the options given below:

The colloidal sol of $SnCl_4$ prefers the adsorption of which ion in the presence of excess $HCl$?

If $x$ gram of gas is adsorbed by $m$ gram of adsorbent at pressure $P$,the plot of $\log \frac{x}{m}$ versus $\log P$ is linear. The slope of the plot is: ($n$ and $k$ are constants and $n > 1$ )

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

The curve that best describes the adsorption of a gas $(x \, g)$ on $1.0 \, g$ of a solid substrate as a function of pressure $(p)$ at a fixed temperature is