Question

In Langmuir's model of adsorption of a gas on a solid surface:

• A. The rate of dissociation of adsorbed molecules from the surface does not depend on the surface covered
• B. The adsorption at a single site on the surface may involve multiple molecules at the same time
• C. The mass of gas striking a given area of surface is proportional to the pressure of the gas
• D. The mass of gas sluicing a given area of surface is independent of the pressure of the gas

Answer 1

The correct option is C The mass of gas striking a given area of surface is proportional to the pressure of the gas

Assuming the formation of a monolayer of the adsorbate on the surface of the adsorbant, it was derived by Langmuir that the mass of the gas adsorbed per gram of the adsorbant is related to the equilibrium pressure according to the equation.

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

x = mass of the gas adsorbed on m gram of the adsorbent.

p = Pressure , a and b are constant.