1. CO2 dissolves in water: When CO2 dissolves in water, it forms carbonic acid (H2CO3):
CO2 (g) + H2O (l) ⇌ H2CO3 (aq)
2. Carbonic acid dissociates: Carbonic acid is a weak acid that partially dissociates in water, releasing hydrogen ions (H+):
H2CO3 (aq) ⇌ H+ (aq) + HCO3- (aq)
3. Increased hydrogen ions: The release of H+ ions increases the concentration of hydrogen ions in the solution.
4. Lower pH: The pH of a solution is a measure of its acidity. A higher concentration of H+ ions results in a lower pH, indicating a more acidic solution.
Consequences of excess CO2 in biological systems:
* Blood acidity: In the human body, excess CO2 in the blood leads to a condition called respiratory acidosis. This can cause various symptoms like headaches, dizziness, and shortness of breath.
* Ocean acidification: The oceans absorb a significant amount of CO2 from the atmosphere. This leads to ocean acidification, which can harm marine life, especially organisms with calcium carbonate shells.
In summary: Excess carbon dioxide in a solution increases the concentration of hydrogen ions, making the solution more acidic. This has significant consequences for biological systems, including the human body and the oceans.
