Here's why:

* pH is a measure of the concentration of hydrogen ions (H+) in a solution.

* Alkyl halides are covalent compounds, meaning they do not dissociate into ions in solution. They do not release H+ ions, nor do they accept H+ ions.

In summary: Alkyl halides are neutral compounds and do not contribute to the acidity or basicity of a solution. They have no measurable pH.