Question & Answer: Aspirin is a monoprotic weak acid with a K a of 3.98 x 10-4 and one dose of aspirin is 500mg……

Aspirin is a monoprotic weak acid with a K a of 3.98 x 10-4 and one dose of aspirin is 500mg.

Write the reaction that controls the pH of aspirin (HC9H7O4)

Given that the average stomach has a pH of 1.4 and a volume of approximately 1 liter, calculate the concentration of aspirin (HA) and its conjugate (A – ) in the stomach.

The conjugate of aspirin is the active drug, and it is absorbed from the stomach into the bloodstream. The pH of the blood stream is 7.4. Assume that all the A – you calculated in (b) is initially absorbed into the bloodstream and calculate what the new ratio of A – /HA will become at this pH.