Answer the question on the basis of passage given below:

Adsorption is a surface phenomenon which can be expressed by means of an emprical relationship known as Freundlich Adsorption isotherm. The relationship is given by

\(\frac{x}{m} = KP^{\frac{1}{n}}\left(n > 1\right)\)

\(x = \)Mass of the gas adsorbed

\(m = \)Mass of adsorbent

\(P = \)Pressure at which adsorption takes place

\(K\) and \(n\) are constant

Choose the incorrect statement with reference to physical adsorption:

Enthalpy of adsorption value \(= 80 - 240 kJ/mol\)

The correct answer is option 2. Enthalpy of adsorption value \(= 80 - 240 kJ/mol\).

The incorrect statement about physical adsorption is Enthalpy of adsorption value = 80 - 240 kJ/mol.

Here is why the other statements are correct and why statement 2 is incorrect:

Non-specific: Physical adsorption is generally non-specific. This means that any gas molecule can potentially be adsorbed on a suitable surface as long as the intermolecular forces between the gas and the surface are favorable.

Reversible: Physical adsorption is a reversible process. The adsorbed molecules can desorb (leave the surface) back into the gas phase if the temperature is increased or the pressure of the gas is decreased.

van der Waals forces: Physical adsorption arises due to weak van der Waals forces between the gas molecules and the adsorbent surface. These forces include London dispersion forces, dipole-dipole interactions, and induced dipole interactions.

Enthalpy of adsorption \((ΔH)\) refers to the change in enthalpy that occurs during the adsorption process. It represents the energy change associated with the adsorption.

The enthalpy change for physical adsorption is typically in the range of \(-80\) to \(-240 kJ/mol|). This is a relatively small range compared to chemical adsorption, which usually has a much higher enthalpy change (more negative value, indicating a more exothermic process).

Statement 2 is incorrect because it specifies a particular range for the enthalpy of adsorption. While the given range is typical, it's not a defining property of physical adsorption. The enthalpy can vary depending on the specific gas and adsorbent involved.