Which one would be expected to happen? If one of the buffers that contribute to pH stability in human blood is carbonic acid (H2CO3). Carbonic acid is a weak acid that when placed in an aqueous solution dissociates into a bicarbonate ion (HCO3-) and a hydrogen ion (H+). Thus, H2CO3 HCO3- + H+ If the pH of the blood increases.
A. A decrease in the concentration of HC03- and an increase in the concentration of both H2CO3 and H2O
B. An increase in the concentration of H2CO3 and a decrease in the concentration of H2O
C. An increase in the concentration of HCO3- and a decrease in the concentration of H2O
D. A decrease in the concentration of H2CO3 and an increase in the concentration of H2O
E. A decrease in the concentration of HCO3- and an increase in the concentration of H2O

On increasing the pH of the blood the hydronium ions concentration will decrease which will result in decrease in concentration of hydronium ions at the equilibrium state of hydrogen carbonate.

Le-Chatelier's principle:

This principle states that if there is any change in the variables of the reaction, the equilibrium will shift in the direction to minimize the effect.

According to Le-Chatelier's principle , on decrease in a concentration of the product the equilibrium moves in forward correction to re-establish itself.

So, on increasing the pH, the hydronium ions concentration will decrease which results in disassociation of more hydrogen carbonate to maintain the pH of the blood.

Hence, the correct answer is option C.