Seawater isn't simply a reservoir of different dissolved salts, like sodium chloride, magnesium sulphate and so on; it has the capability to react in different ways, one being with carbon dioxide in the atmosphere, modifying its concentration and buffering its anthropogenic increase. Oceans cover about 71% of the earth surface, so even slight variations of critical parameters, like pH, salinity and so on have a huge effect on global climate, and therefore on our way of life. The reactions involved, however, cannot be mathematically treated with the usual chemistry textbook solutions. Seawater has a high salt content (or ionic strength), and the potency of its ionic charge density totally alters the equilibrium constants, rendering such solutions (which are based on pure water) of little use. The calculation parameters are further affected by high pressures to be found in the dark abysses.

In this web-site, the appropriate algorithms for chemical equilibria in seawater are proposed in a plain and simple basic language that’s ready for use, or even modification, by the reader. There is no need for advanced math or programming expertise. Equilibria are solved by iterative procedures that require no differential calculus, and instructions are given on how to access executable codes. There is even an introduction to basic chemistry calculations in solutions in the first three chapters, thereby making the manual completely user friendly for experts and amateur enthusiasts alike.