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

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

Langmuir adsorption isotherm is represented as

$\frac{x}{m}=\frac{ap}{1+bp}$

where,

a and b are Langmuir parameters.

If pressure p is very high then bp >> 1, hence $1+bp\approx bp$

$\therefore \frac{x}{m}=\frac{ap}{bp}=\frac{a}{b}=constant$