Final answer:
Carboxylic acids are the most acidic functional group, followed by protonated amines, hydrochloric acid, water, amine, alkyne, and alkane.
Step-by-step explanation:
The acidity of functional groups can be ranked based on their ability to donate protons. In general, carboxylic acids are the most acidic, followed by protonated amines, hydrochloric acid, water, amine, alkyne, and alkane.
Acidity increases as you move from left to right in this ranking.
For example, hydrochloric acid is more acidic than water because the chloride ion is a stronger conjugate base than the hydroxide ion.