Question

At high pressure, Langmuir adsorption isotherm takes the form:

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

Answer 1

The correct option is B $\frac{x}{m}=\frac{a}{b}$

Langmuir adsorption isotherm is mathematically given by $\frac{x}{m}=\frac{aP}{1+bP}$.

At high pressure bP >>> 1 and $1+bP\equiv bP$.

So, at high pressure the Langmuir adsorption isotherm equation is modified to $\frac{x}{m}=\frac{aP}{bP}$ which is equal to $\frac{x}{m}=\frac{a}{b}$.

So the correct option is B.