Hint: The acidity of a species depends on its power to
remove hydrogen ions.
Step 1: Acidic character dependence
If an electron-withdrawing group is attached to a benzene ring then the group will attracts the ring electrons which facilitate the release of hydrogen ions and the species become more acidic.
If an electron-donating group is attached to a benzene ring then the group will supply electrons to the ring which does not release hydrogen ions easily and the species become least acidic.
Step 2: Acidity comparison
This compound has three electron-withdrawing groups
. So it will withdraw the electrons from the bond and the bond breaks easily. So, it is most acidic.
This compound has one electron-withdrawing group
. So, it will also pose higher acidity.
This compound has an electron-donating group so, it
is the least acidic.
This compound is moderately acidic due to the presence of the hydroxyl group.
The order of acidity of the compounds is
Correct Option :