Question

What is the equation form of Langmuir adsorption isotherm under high pressure?

• A. $ \frac{x}{m}=\frac{a}{b} $
• B. $ \frac{x}{m}=ap $
• C. $ \frac{x}{m}=\frac{1}{ap} $
• D. $ \frac{x}{m}=\frac{b}{a} $

Answer 1

Answer: (A)

Langmuir adsorption isotherm is represented as
$\frac{x}{m}=\frac{a p}{1+b p}$
where,
$a$ and $b$ are Langmuir parameters.
If pressure $p$ is very high then $b p>>1$,
hence $1+b p \approx b p$
$\therefore \frac{x}{m}=\frac{a p}{b p}=\frac{a}{b}=$ constant