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

In chromatography,which of the following statements is incorrect for $R_f$?

The extent of adsorption of a gas on a solid depends on .....

The extent of adsorption of a gas on a solid depends on:

Given below are two statements: one is labelled as Assertion $(A)$ and the other is labelled as Reason $(R)$.
Assertion $(A)$: In expensive scientific instruments,silica gel is kept in watch-glasses or in semipermeable membrane bags.
Reason $(R)$: Silica gel adsorbs moisture from air via adsorption,thus protects the instrument from water corrosion (rusting) and/or prevents malfunctioning.
In the light of the above statements,choose the correct answer from the options given below:

In a Freundlich adsorption isotherm,if the slope is unity and $k$ is $0.1$,the extent of adsorption at $2 \ atm$ is $(\log 2 = 0.30)$