Freundlich adsorption isotherm fails at which of the following condition?
Freundlich adsorption isotherm fails at which of the following condition?
High temperature
Low temperature
High pressure
Low pressure
Solution
The Freundlich adsorption isotherm is the mathematical representation for the variation of the extent of adsorption $(x / m)$ with pressure $(p)$ at a given temperature.
$
x / m=k \cdot p^{1 / n}(n>1)
$
where ' $x$ ' is the mass of the gas adsorbed on mass ' $m$ ' of the adsorbent at pressure ' $p$ '. ' $k$ ' and ' $n$ ' are constants that depend on the nature of the adsorbent and the gas at a particular temperature. Experimentally, it was determined that the extent of gas adsorption varies with pressure raised to the power $1 / n$ until saturation pressure $p_s$ is reached. At high pressure, $x / m$ becomes independent of pressure. Hence, Freundlich equation becomes
$
x / m=k \cdot p^0 \Rightarrow x / m=k
$
Thus, the Freundlich adsorption isotherm fails at higher pressure