Question

In a buffer solution of acetic acid/acetate at pH = pKa = 4.76, adding aspirin (pKa = 3.5) shifts the reaction to the right. Does the degree of dissociation of aspirin depend on the pH of the solution or the reaction with the buffer's conjugate base?

a) Depends on the pH
b) Depends on the buffer
c) Depends on the aspirin concentration
d) Depends on the temperature

Answer 1

The degree of dissociation of aspirin depends on the pH of the solution.

Step-by-step explanation:

The degree of dissociation of aspirin depends on the pH of the solution.

When aspirin (pKa = 3.5) is added to a buffer solution of acetic acid/acetate at pH = pKa = 4.76, the reaction shifts to the right.

Aspirin acts as a weak acid, and its degree of dissociation depends on the pH of the solution. In a more acidic solution, more aspirin molecules will dissociate to form the conjugate base, while in a more basic solution, fewer aspirin molecules will dissociate.

So, the degree of dissociation of aspirin depends on the pH of the solution, not on the reaction with the buffer's conjugate base.