Acetic acid (CH₃COOH) has a pK_a of 4.74, while ethanol (CH₃CH₂OH) has a pK_a of about 16. Which molecule is more acidic? A) acetic acid, because it has a higher pK_a B) acetic acid, because it has a lower pK_a C) ethanol, because it has a higher pK_a D) ethanol, because it has a lower pK_a E) They have the same acidity.

Question

Quizplus · Accepted Answer

The lower the pKa value, the stronger the acid. Acetic acid has a lower pKa value (4.74) than ethanol (16), which means it is a stronger acid. Therefore, option B is the correct answer.

Acetic Acid (CH3COOH) Has a PKa of 4

Acetic Acid (CH₃COOH) Has a PK_a of 4