For adsorption of a gas on a solid, the plot of log $x / m$ vs log $P$ is linear with slope equal to ( $n$ being whole number)

• A

  $k$
• B

  $\log k$
• C

  $n$
• Correct answer
  D

  $\frac{1}{n}$

Solution

According to Freundlich adsorption isotherm, at intermediate pressure, extent of adsorption $$ \frac{x}{m}=k \mathrm{P}^{1 / n} \text { or } \log \frac{x}{m}=\log k+\frac{1}{n} \log \mathrm{P} $$
plot of $\log \frac{x}{m}$ vs log $\mathrm{P}$ is linear with slope $=\frac{1}{n}$

Hence, the correct answer is option: 'D'.