The pKaoof acetylsalicyclic acid (aspirin) is 3.5. The pH of gastric juice in the human stomach is about 2 to 3 and the pH in small intestine is about 8. Aspirin will be
ionized in the small intenstine and almost unionized in the stomach
In water, acids stronger than water are all completely ionized. So the strongest acid in water will be H3O+. Stronger acids than water will be fully ionized. Weaker acids will undergo very small ionization.
From the given data, the gastric juice (stomach) is much more acidic than aspirin and thus very less ionization. On the other hand, the intestine is somewhat basic. There aspirin will behave like a strong acid and dissociate very appreciably