What compound forms when CO₂ dissolves in water?

When carbon dioxide (CO₂) dissolves in water, it undergoes a chemical reaction that forms carbonic acid (H₂CO₃). This occurs as CO₂ reacts with H₂O, resulting in the generation of carbonic acid, which is a weak acid that can partially dissociate into bicarbonate and hydrogen ions. This process is important in various biological and environmental systems, such as regulating pH in blood and maintaining the acid-base balance in aquatic ecosystems.

The formation of carbonic acid from dissolved CO₂ is a crucial aspect of the carbon cycle, influencing both ocean chemistry and atmospheric conditions. Understanding this reaction is vital for studying topics like respiration, photosynthesis, and climate change impacts, where CO₂ levels play a significant role.