JEE Main 2017 — Surface Chemistry Question with Solution

According to Freundlich adsorption isotherm, in the median range of pressure

       $$\frac{x}{m}\propto P^{\frac{1}{n}}$$

$$\Rightarrow$$  $$\frac{x}{m}$$ = kP$${}^{\frac{1}{n}}$$

taking log both sides, we get,

log$$\frac{x}{m}$$ = logk + $$\frac{1}{n}$$ logP

Here in graph between log$$\frac{x}{m}$$ and logP, slope is $$\frac{1}{n}$$ and intercepts = log k.

Given that,

slope = 0.5

$$\therefore$$ $$\frac{1}{n}$$ = 0.5

$$\Rightarrow$$   n = 2

$$\therefore$$ $$\frac{x}{m}$$ = kP$${}^{\frac{1}{2}}$$ = k$$\sqrt{P}$$

$$\therefore$$  Adsorption is proportional to the square root of pressure.