Question

Which of the following statements is incorrect regarding a physisorption process?

• A. There are van der Waal's interactions between the adsorbate and the adsorbent
• B. The process predominates at low temperature
• C. The process cannot proceed beyond a monolayer
• D. The process is reversible

Answer 1

The correct option is C The process cannot proceed beyond a monolayer

In physisorption, there is van der Waal's interaction between the adsorbate and the adsorbent e.g. dispersion or dipolar interaction.

Energy released when a particle is physisorbed is of the same order of magnitude as the enthalpy of condensation. Such small energy can be absorbed as vibrations of the lattice and dissipated as thermal motion, and a molecule bouncing across the surface will gradually lose its energy i.e. this process predominates at low temperature. As temperature increases, physisorption decreases.

Physisorption can be monolayered or multilayered.

Physisorption process is a reversible process.