Carbonic acid is an important buffer

Question

Carbonic acid is an important buffer (pH~7.4) in biological systems and can partially breakdown according to the following reaction:

H2CO3 ↔ H+ + HCO3-

a. Indicate which components are the weak acid and conjugate base.

b. Which way would the reaction go if there was a sudden increase in blood pH? Why?

c. Which way would the reaction go if there was a sudden decrease in blood pH? Why?

Answer 1

A. The weak acid is carbonic acid, H2CO3 since it has a proton and the conjugate base is bicarbonate, HCO3- since it is missing a proton.

B. An increase in pH means that there is a decrease in protons, so according to Le Chatelier's principle, the equilibrium would end up shifting right in order to relieve stress on the system.

C. A decrease in pH means that there is an increase in protons, so according to Le Chatelier's principle, the equilibrium would end up shifting left in order to relieve stress on the system.