Whether the ortho-carboxyl substituent acts as an intramolecular general-base catalyst or as an intramolecular nucleophilic catalyst can

Question:

Whether the ortho-carboxyl substituent acts as an intramolecular general-base catalyst or as an intramolecular nucleophilic catalyst can be determined by carrying out the hydrolysis of aspirin with 18O-labeled water and determining whether 18O is incorporated into ortho-carboxyl-substituted phenol. Explain the results that would be obtained with the two types of catalysis