Question

The $_pK_a$ of acetylsalicylic acid (aspirin) is $3.5$.The $H$ of gastric juice in human stomach is about $2.3$ and the $pH$ in the small intestine is about $8$. Aspirin will be

• A. unionized in the small intestine and in the stomach
• B. completely ionised in small intestine and in the stomach
• C. ionised in the stomach and almost decrease in the small intestine
• D. ionised in the small intestine and almost unionised in the stomach

Answer 1

Answer: (D)

ionised in the small intestine and almost unionised in the stomach

Answer 2

Aspirin is a weak acid. Due to common ion effect it is unionised in acid medium but completely ionised in alkaline medium.