Between water and an $NaCl$ solution,which will have a higher surface tension? (Effect of solute on surface tension)

Which among the following gases is adsorbed to a greater extent at similar conditions of temperature and pressure if the adsorbent remains same?

When $O_{2}$ is adsorbed on a metallic surface,electron transfer occurs from the metal to $O_{2}$. The $TRUE$ statement$(s)$ regarding this adsorption is(are)
$(A)$ $O_{2}$ is physisorbed
$(B)$ heat is released
$(C)$ occupancy of $\pi_{2p}^{*}$ of $O_{2}$ is increased
$(D)$ bond length of $O_{2}$ is increased

Assertion $(A)$: van der Waals' forces are responsible for chemisorption.
Reason $(R)$: High temperature is favourable for chemisorption.
The correct answer is

The Freundlich adsorption isotherm is given by:

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