Question

What is the optimal `"pH"` for acid hydrolysis?

Answer 1

I'm not sure what you mean by acid hydrolysis; you could be implying acid-catalyzed hydrolysis, in which case you may mean hydrolysis of amides or esters.

Either way, it requires acidic conditions, which is obvious from the name "acid-catalyzed hydrolysis". i.e. the pH should be less than `7` for optimal conditions.

However, our bodily functions would be far from optimal at acidic pH's. We function best at approximately pH `7.4` and `37^@ "C"`.

In fact, enzyme hydrolysis of the "amide backbone" of a protein does occur in the human body, and optimally should not force the body to assume irregular pH's or temperatures (if it does, we'd be quite uncomfortable whenever this occurs).

I go into the full mechanism of the catalytic triad which acts to make this occur, here.

(Basically, the collaboration of three amino acids off of the backbone of trypsin, for instance, collectively becomes a trick of altering pKas so that each of them can play a role in this "polyamide" hydrolysis.)