What Keeps Sea Water Alkaline Despite the Presence of Carbon Dioxide?

[morrobay]

Besides temperature influencing CO₂ in the oceans.
There is also CO₂ partial pressures in ocean and atmosphere , Henry's Law
to consider.
There is local salinity to consider.
There is CO₂ uptake by marine phytoplankton and algae to consider.
Although all your posts are correct in a strict inorganic chemistry context
the carbon dioxide cycle in the oceans is more complex and synergistic than inorganic chemistry alone.

 

[Borek]

the carbon dioxide cycle in the oceans is more complex and synergistic than inorganic chemistry alone.

So why do you try to answer the initial question with single nonsensical reaction equations?

 

[morrobay]

So why do you try to answer the initial question with single nonsensical reaction equations?

You don't seem to understand that a single reaction can have products that are
influenced by more than one factor in the surroundings;

Ca⁺⁺ + 2HCO₃^- <> Ca(HCO₃)₂ <> CaCO₃ + H₂O + CO₂
Here is the reaction with products that are influenced by temperature, partial pressures,
salinity and photosynthesis . Do you understand that marine plants consume the CO₂ in the above product and hence stop this reaction:
CO₂ + H₂O > H⁺ + HCO_3^-
thereby maintaining alkalinity ?
Mabey you should reread the OP and brush up on photosynthesis

 

[Borek]

You are just trolling, and I am telling it for the second (and last) time. You showed you have no idea about the system much earlier, in many ways, proposing presence of Ca(OH)₂:

Ca(OH)₂ + CO₂ >>shellfish> CaCO₃ + H₂O

suggesting existence of metallic calcium:

Ca + 2 H₂O ---> Ca(OH)₂ + H₂

calcium oxide:

CaO + H₂O --> Ca(OH)₂

later you suggested that reaction which produces carbon dioxide - acid anhydride:

Ca⁺⁺ + 2HCO_3^- --> Ca(HCO₃)₂ --> CaCO₃ +H₂O + CO₂

doesn't change pH, now you call for photosynthesis to explain what happens to carbon dioxide. Trick is, if carbon dioxide is produced and then consumed, and speeds of both reactions are identical so that pH is maintained, that's a classic example of a steady state system, different from the one I was thinking about - but conceptually similar.