In comparing the H+ ion concentration between the stomach and the small intestine, the stomach has a significantly higher concentration of H+ ions.
The pH of the gastric juice in the stomach typically ranges from 1.5 to 3.5, indicating a very high concentration of hydrogen ions. This equates to an H+ concentration roughly between 0.03 moles per liter (at pH 3.5) and 0.01 moles per liter (at pH 1.5).
On the other hand, the pH of the small intestine is more neutral, generally around 6 to 7, which results in a much lower concentration of H+ ions. For instance, at pH 6, the H+ concentration is approximately 0.000001 moles per liter and at pH 7 it is 0.0000001 moles per liter.
To find the ratio of H+ concentration between the stomach and small intestine, we can take a specific example. Let’s use pH 3.5 for the stomach (0.03 moles/L) and pH 6 for the small intestine (0.000001 moles/L):
Ratio = Concentration in stomach / Concentration in small intestine = 0.03 / 0.000001 = 30,000.
This indicates that the concentration of H+ ions in the stomach is about 30,000 times higher than that in the small intestine. Thus, the stomach is equipped for the highly acidic environment needed for digestion, while the small intestine has a more neutral pH for enzymatic activities and nutrient absorption.