Name: Colloids and Their Properties
Uploaded: 2019-07-19
Duration: 4 min 49 s
Description: Have you ever come across a substance that is not a suspension but also not a true solution? It's a colloidal suspension. Let's learn about the properties of...

Question

Determine the value of

' n'

in Freundlich adsorption isotherm in the case of high pressure.

Accepted Answer

The variation of extent of adsorption $\frac{x}{m}$ with pressure $(P)$ at a particular temperature is known as adsorption isotherm. At high pressure, the graph becomes almost constant which means that $\frac{x}{m}$ becomes independent of pressure shown in the figure.

This may be expressed as, $\frac{x}{m}$ = constant or $\frac{x}{m} \propto P^{\circ}$ $(∴ P^{\circ} = 1)$

$\frac{x}{m} = {kP}^{\circ}$

Calculation of $k$ and $n$ of adsorption isotherm. The constants $k$ and $n$ can be determined as explained below: $\log \frac{x}{m} = \log k + \frac{1}{n} \log P$ . Thus, if we plot a graph between log $\frac{x}{m}$ on $y - axis$ (ordinate) and $\log P$ , on $x - axis$ (abscissa), straight-line will be obtained. This also shows the validity of Freundlich isotherm. The slope of the line is equal to $\frac{1}{n}$ and the intercept is equal to $\log k$ .

Determine the value of $' n'$ in Freundlich adsorption isotherm in the case of high pressure.

Important Questions on Surface Chemistry

Learn and Prepare for any exam you want !

Determine the value of 'n' in Freundlich adsorption isotherm in the case of high pressure.

Important Questions on Surface Chemistry

Learn and Prepare for any exam you want !

Determine the value of $' n'$ in Freundlich adsorption isotherm in the case of high pressure.