Which among the following is an example of sorption?

The Freundlich adsorption isotherm varies with temperature according to the figure given below. Choose the correct option accordingly.

To form a complete monolayer of acetic acid on $1 \ g$ of charcoal,$100 \ mL$ of $0.5 \ M$ acetic acid was used. Some of the acetic acid remained unadsorbed. To neutralize the unadsorbed acetic acid,$40 \ mL$ of $1 \ M$ $NaOH$ solution was required. If each molecule of acetic acid occupies $P \times 10^{-23} \ m^2$ surface area on charcoal,the value of $P$ is $\qquad$
[Use given data : Surface area of charcoal $= 1.5 \times 10^2 \ m^2 \ g^{-1}$; Avogadro's number $(N_A) = 6.0 \times 10^{23} \ mol^{-1}$]

Adsorption is multilayer in the case of

Animal charcoal is used in decolourising liquids because it is a good

Why are powdered substances more effective adsorbents than their crystalline forms?