carbonic

Question 1

One of the systems controlling the pH of blood is the
carbonic acid-hydrogencarbonate buffer system.
H2CO3 _` H+
+ HCO3
–
Explain how this buffer system helps to control the pH of blood when extra
carbon dioxide is present due to strenuous exercise

Answer 1

carbon dioxide dissolved in the blood forms carbonic acid (and
so this concentration increases) (1)
 the equilibrium will shift to the right and produces more H+/acid
ions (1)
 the (high) concentration of hydrogencarbonate ions suppress the
ionisation of carbonic acid (to help to control pH)
or
the (large) reservoir/excess of hydrogencarbonate ions combine
with the H+ ions (to help to control blood pH) (1)