Shells of mussels (clams) are mainly of calcium carbonate. Usually the shell is stable and its content is in equilibrium with the surrounding. Mussels need to built up or reduce their shell, however, for additional surrounding.

Assume that the concentration of CA2+ ions in seawater and in the vicinity of a mussel bank is

(1.0 X 10^-2) M. Also, assume that the total concentration of "inorganic carbon" in seawater (this is carbon in chemical species with carbonate entities is (2.3 X 10^-3) M

Calculate the pH (correct to two decimals) of the water in the vicinity of mussels so that their shell remains stable.

discuss the implication of an increasing amount of CO2 in the atmosphere on the PH of seawater and , ultimately, on the existence of calcifying organisms such as corals, marine plankton and shell fish.