What happens when CO2 dissolves in seawater?

What happens when CO2 dissolves in seawater?

• A. It forms carbonic acid, lowering the pH of seawater.
• B. It forms sulfuric acid.
• C. It increases salinity.
• D. It neutralizes pH.

Answer: (A)

When CO2 dissolves in seawater, it reacts with water to form carbonic acid, a weak acid. This carbonic acid partially dissociates to release hydrogen ions and bicarbonate, so the water becomes more acidic (pH drops). In other words, CO2 addition shifts the carbonate system toward more H+ and bicarbonate, lowering pH and leading to ocean acidification. This is not sulfuric acid formation, it does not raise salinity, and it does not neutralize pH—rather, it makes the seawater more acidic.

When CO2 dissolves in seawater, it reacts with water to form carbonic acid, a weak acid. This carbonic acid partially dissociates to release hydrogen ions and bicarbonate, so the water becomes more acidic (pH drops). In other words, CO2 addition shifts the carbonate system toward more H+ and bicarbonate, lowering pH and leading to ocean acidification. This is not sulfuric acid formation, it does not raise salinity, and it does not neutralize pH—rather, it makes the seawater more acidic.