Freundlich adsorption isotherm fails at which of the following condition?

Which of the following statements is incorrect?

For the adsorption of hydrogen on platinum,the activation energy is $30 \ kJ \ mol^{-1}$ and for the adsorption of hydrogen on nickel,the activation energy is $41.4 \ kJ \ mol^{-1}$. The logarithm of the ratio of the rates of chemisorption on equal areas of the metals at $300 \ K$ is $........$ (Nearest integer). Given: $\ln 10 = 2.3$,$R = 8.3 \ J \ K^{-1} \ mol^{-1}$.

Activated charcoal is used to remove colouring matter from pure substances. It works by

When is the term 'sorption' used?

$A$ mixture of substances $A, B, C, D$ is subjected to column chromatography. The degree of adsorption is in the order of $D > B > C > A$. The column is eluted with a suitable solvent. Identify the correct statement with respect to the separation of the mixture.