Fig. 10 - This may look like a mess, but the biggest
solution in the world is of course the ocean, and here's a bird's-eye
view of the acid-base chemistry of seawater.
Note especially that
- the only really important pH on this graph is 8, the approximate pH
of the natural ocean.
- The pH of the ocean is controlled mainly by the carbonate system because
it is more concentrated than the two minor buffering systems, borate and
- The surface waters of the ocean are everywhere supersaturated in calcium
bicarbonate and in CO2 , as shown by the dotted curves (the
"ss[CO2 ]" label is the illegible one-- sorry!)
- Ion-pair complexes such as MgOH+ are significant species in seawater;
there are many others.