Pardon my ignorance (my field is electronics) but are you saying that a reduction in pH from 8.2 to 8.1 i.e. moving toward the neutral point, DOES result in an increase in absolute corrosiveness (it's ability to attack a metal or in this case calcium carbonate)? I understand it means an increase in the number of hydrogen ions but I thought that solution had to be genuinely acidic (pH <7)for it to be able to dissolve sea shells.
If I was wrong I owe some people some humble apologies
I think "corrosiveness" is an unhelpful term. The "neutral" pH of 7 is nothing special - it's merely the result of the dissociation constant (10^-7 M) of water molecules in pure water at standard temperature and pressure or thereabouts. Calling solutions with pH<7 acidic and those with pH>7 basic or alkaline is just shorthand.
Seawater is actually extremely corrosive to metals due to the high availability of nonmetallic ions - just ask any north sea oily.
Look, chaps....pardon a mathematician among natural scientists, but if a solution moves towards a pH of 7 it becomes less 'corrosive', surely? If it is neither oxidising nor reductive it will tend to leave things alone?
My hours spent in Stochastic Chemistry are haunting me right now.
My feeble memory is telling me that the fundamental difference between Acids and Bases was the concentration of H+ ions vs OH- ions. Acids had more H+ than OH- and bases had more OH- vs H+, which was their tendency to oxidize or reduce.
My memory also brings back images of mixing Strong Bases with Strong Acids which resulted in lovely exothermic reactions.