Review Questions: Weak interactions, amino acids, and pKa

Aspirin is a weak acid with a pKa of 3.5. It is absorbed into the blood through the cells lining the stomach and the small intestine. Absorption requires passage through the plasma membrane, the rate of which is determined by the polarity of the molecule: charged and highly polar molecules pass slowly, whereas neutral hydrophobic ones pass rapidly. The pH of the stomach contents is about 1.5, and the pH of the contents of the small intestine is about 6. Is more aspirin absorbed into the bloodstream from the stomach or from the small intestine?

Stomach; the neutral form of aspirin present at the lower pH is less polar and passes through the membrane more easily

Does a strong acid have a greater or lesser tendency to lose its proton than a weak acid?

greater

Does the strong acid have a higher or lower Ka than the weak acid?

higher

Does the strong acid have a higher or lower pKa than the weak acid?

lower