Ionization States of Aspirin

The video tutorial explores the concept of protonation states and pKa, focusing on acetylsalicylic acid (aspirin). It explains the structure of aspirin and its pKa value of 3.5, and how this relates to the pH levels in the human stomach and small intestine. The tutorial discusses how the pH being below or above the pKa affects the protonation state of aspirin, leading to ionization in the small intestine and remaining protonated in the stomach.

What is the pKa value of acetylsalicylic acid, also known as aspirin?

• 5.5

• 3.5

• 2.5

• 4.5

What is the typical pH range of gastric juice in the human stomach?

• 3 to 4

• 4 to 5

• 2 to 3

• 1 to 2

How does the pH of a solution compare to the pKa to determine if a carboxyl group will be protonated?

• pH equal to pKa means deprotonated

• pH above pKa means protonated

• pH below pKa means deprotonated

• pH below pKa means protonated

What happens to the carboxyl group of aspirin when the pH is significantly above 3.5?

• It remains protonated

• It becomes deprotonated

• It forms a new compound

• It dissolves completely

In which environment is the pH significantly higher than the pKa of aspirin?

• Bloodstream

• Stomach

• Liver

• Small intestine

What is the ionization state of aspirin in the small intestine?

• Dissolved

• Neutral

• Deprotonated

• Protonated

What is the ionization state of aspirin in the stomach?

• Dissolved

• Protonated

• Deprotonated

• Neutral

Which option correctly describes the ionization state of aspirin in both the stomach and small intestine?

• Non-ionized in the stomach, ionized in the intestine

• Ionized in the stomach, non-ionized in the intestine

• Non-ionized in both

• Ionized in both