Question

6. Between 1751 and 1994, the pH of the ocean changed from 8.25 to 8.14. By 2100, the pH of the ocean is expected to be between 7.64-7.84. Is this an increase or decrease in pH? Does that correspond to an increase or a decrease in acidity of the ocean? Explain how this data is or is not consistent with what you observed in the lab about the change in pH of seawater and freshwater from carbon dioxide. What do you think the term ocean acidification means?

Answer 1

pH = 7 means, it is neutral ,(aidic pH < 7 ; Basic pH >7)  If pH of ocean is around 8.2 means it is less basic. By 2100, the pH of the ocean is between 7.64 to 7.84 which means pH get reduced towards acidic, that is, increase in acidity of ocean (pH decreases). If CO₂ gas is increased on the surface of water/seawater, CO₂ will be dissolved in water and it becomes carbonic acid, H₂CO₃, HCO₃^- , CO₃^2-. hence water/seawater becomes acidic, that is, pH decreases, or H⁺ ion concentration increases. Ocean acidicfing means, H⁺ ion conc. increases, because of CO^₂gas increases on the atmosphere.