Question:
For Freundlich adsorption isotherm, a plot of $\log (\mathrm{x} / \mathrm{m})$ ( $\mathrm{y}$-axis) and $\log \mathrm{p}$ ( $\mathrm{x}$-axis) gives a straight line. The intercept and slope for the line is $0.4771$ and 2, respectively. The mass of gas, adsorbed per gram of adsorbent if the initial pressure is $0.04 \mathrm{~atm}$, is__________$\times 10^{-4 \mathrm{~g}}$
$(\log 3=0.4771)$
Solution:
$\frac{\mathrm{X}}{\mathrm{m}}=\mathrm{KP}^{1 / \mathrm{n}}$
$\log \left(\frac{x}{m}\right)=\frac{1}{n} \log P+\log K$
slope $=\frac{1}{n}=2$
intercept $=\log \mathrm{K}=0.4771$
$\mathrm{K}=3$
mass of gas adsorbed per gm of adsorbent $=\frac{x}{m}$
$\frac{x}{m}=3 \times(0.04)^{2}=48 \times 10^{-4}$