Eli’s Mind

Seawater contains a complex carbonate system that includes dissolved carbon dioxide, bicarbonate ions (HCO3-), and carbonate ions (CO3^2-). The concentration of each species is in dynamic equilibrium, influenced by temperature, pressure, and the partial pressure of atmospheric CO2.

The process by which the oceans take up CO2 from the atmosphere involves an acid-base reaction. When CO2 is absorbed by seawater, it reacts with water (H2O) to form carbonic acid (H2CO3), which is a weak acid:

CO2 + H2O ⇌ H2CO3

The carbonic acid then dissociates into bicarbonate ions and hydrogen ions (H+):

H2CO3 ⇌ HCO3- + H+

This bicarbonate ion can also undergo further dissociation into carbonate ions and additional hydrogen ions:

HCO3- ⇌ CO3^2- + H+