Question

The slope of the straight line graph between log x/m and log P for the adsorption of a gas on solid at constant temperature is:
(Where, x = mass of the gas adsorbed, m = mass of adsorbent, P = pressure)

• A. $1/n$
• B. $n$
• C. $\log k$
• D. $k$

Answer 1

The correct option is A $1/n$

From the parameters given, we can say that here we are considring Freundlich adsorption isotherm.
The equation for Freundlich adsorption isotherm is
$\frac{x}{m}=k{P}^{\frac{1}{n}}$
On taking logarithm on both side, we obtain
$\log \frac{x}{m}=\log k+\frac{1}{n}\log P$.
$\therefore$Plot of $\log x/m$ versus $\log P$ will be linear with slope $=\frac{1}{n}$


Plotting of Freundlich adsorption isotherm.