Question

Increased atmospheric CO₂ concentrations might have what effect on seawater?

A) Seawater will become more acidic, and bicarbonate concentrations will decrease.
B) Seawater will become more acidic, and carbonate concentrations will decrease.
C) Seawater will become more acidic, and carbonate concentrations will increase.
D) Seawater will become more alkaline, and carbonate concentrations will decrease.
E) There will be no change in the pH of seawater, because carbonate will turn to bicarbonate."

Answer 1

Increased atmospheric CO₂ concentrations lead to ocean acidification, making seawater more acidic and lowering carbonate concentrations, which is detrimental to marine organisms that rely on calcium carbonate for their exoskeletons.

Step-by-step explanation:

The increase in atmospheric CO₂ concentrations can have significant impacts on seawater chemistry. One of the primary effects is the increase in ocean acidity, which is also known as ocean acidification. When CO₂ from the atmosphere dissolves in seawater, it reacts to form carbonic acid, which then dissociates into bicarbonate and hydrogen ions.

As seawater becomes more acidic due to higher CO₂ levels, the concentration of carbonate ions decreases. Carbonate ions are important because they combine with calcium ions to form calcium carbonate, which marine organisms use to create their shells and skeletons. With fewer carbonate ions available, organisms such as corals and shellfish struggle with calcification, leading to weakened shells and skeletal structures.