When the bicarbonate buffer system buffers the strong acid HCl:
A)carbonic acid is formed, which only slightly lowers pH
B)sodium chloride is formed, which raises pH
C)water is formed, which lowers pH
D)sodium chloride is formed, which lowers pH

Question

Quizplus · Accepted Answer

When the bicarbonate buffer system reacts with strong acid HCl, it forms carbonic acid (H2CO3) and chloride ions (Cl-). Carbonic acid dissociates to form bicarbonate ions (HCO3-) and H+ ions. However, since this reaction is reversible, some of the bicarbonate ions combine with H+ ions to form carbonic acid, which can again dissociate to give bicarbonate and H+ ions. Overall, this system acts as a buffer and helps to resist changes in the pH of a solution. In this case, the added H+ ions get neutralized by the bicarbonate ions, which leads to the formation of carbonic acid. This slightly lowers the pH of the solution, making option A the correct answer.

When the Bicarbonate Buffer System Buffers the Strong Acid HCl