Question

Plot of log (x/m) against log P is a straight line inclined at an angle of ${45}^{\circ }$. When the pressure is 0.5 atm and the proportionality constant in Freundlich's equation is 10, the amount of solute per gram of adsorbent will be:

• A. 1 g
• B. 2 g
• C. 3 g
• D. 5 g

Answer 1

The correct option is D 5 g

According to Freundlich adsorption isotherm,
$\frac{x}{m}=k{P}^{\frac{1}{n}}$
$\Rightarrow log\left(\frac{x}{m}\right)=logk+\frac{1}{n}logP$
Since it is a straight line,
Slope= $tan{45}^o=\frac{1}{n}$
$\Rightarrow n=1$
Given, when the pressure is 0.5 atm and Freundlich parameter is 10, So
$\frac{x}{m}=10(0.5{)}^1$
$\Rightarrow \frac{x}{m}=5g$
Therefore the amount of solute per gram of adsorbent will be 5 g.