Question

how does the carbon dioxide dissolved in seawater relate to its pH in a few sentences

Answer 1

Carbon dioxide (CO2) dissolved in seawater reacts with water to form carbonic acid (H2CO3), which then dissociates into bicarbonate (HCO3-) and hydrogen ions (H+). The increase in hydrogen ions leads to a decrease in pH, making the water more acidic. This process is a significant factor in ocean acidification, which affects marine ecosystems and organisms, particularly those with calcium carbonate structures, like corals and shellfish. As CO2 levels in the atmosphere rise, more CO2 is absorbed by the ocean, further lowering its pH over time.