Question

The correct assumption(s) required to derive Langmuir adsorption isotherm is/are

• A. Adsorption is limited to a monolayer on adsorbing surface
• B. All binding sites on adsorbing surface are identical.
• C. Adsorption of a molecule on a site enhances binding of other molecules on neighboring sites
• D. Rate of adsorption and rate of desorption are equal at equilibrium.

Answer 1

The Correct Option is A, B, D

• (A) This assumption is correct. Langmuir adsorption model assumes that adsorption occurs in a single monolayer, meaning only one molecule adsorbs at each site.
• (B) This is also correct. Langmuir model assumes that all adsorption sites are identical and have the same energy of adsorption.
• (C) This assumption is incorrect. Langmuir adsorption model assumes that adsorption on one site does not affect adsorption on neighboring sites (no interaction between adsorbed molecules).
• (D) This is correct. At equilibrium, the rate of adsorption equals the rate of desorption in the Langmuir adsorption model.

Thus, the correct answers are (A), (B), and (D)