Commodity Fumigation License Practice Exam

Which term describes the binding of the fumigant on the surface?

1. Absorption

2. Adsorption

3. Desorption

4. Penetration

The correct answer is: Adsorption

The term that describes the binding of the fumigant on the surface is adsorption. This process involves the accumulation of molecules, such as fumigants, on the surface of a solid or liquid without penetrating into the material. In adsorption, the molecules adhere to the surface due to various forces, such as van der Waals forces or chemical bonds, forming a layer that is distinct from the bulk material. Understanding the concept of adsorption is crucial in fumigation because it affects how effectively a fumigant can penetrate and interact with the target material, such as grains or other commodities. Efficient fumigation relies on the fumigant remaining available in the atmosphere to diffuse into the material being treated rather than being bound to surfaces where it could be less effective. Absorption, on the other hand, involves the uptake of a substance into the bulk of a material, which is not applicable in this context. Desorption refers to the release of the absorbed or adsorbed substance from the surface back into the surrounding medium, while penetration relates to the movement of the fumigant into the material. These processes are distinct from adsorption and highlight the importance of knowing how fumigants behave on surfaces during the fumigation process.