What does carbon dioxide in solution react with to form a weak acid?

When carbon dioxide is dissolved in water, it undergoes a reaction that produces carbonic acid. This reaction can be represented by the equation:

[ \text{CO}_2 + \text{H}_2\text{O} \leftrightarrow \text{H}_2\text{CO}_3 ]

Here, carbon dioxide (CO2) combines with water (H2O) to form carbonic acid (H2CO3), which is classified as a weak acid because it partially ionizes in solution. This means that not all of the carbonic acid molecules will dissociate into hydrogen ions (H+) and bicarbonate ions (HCO3-), making it a weak acid compared to stronger acids, which fully dissociate in solution.

Understanding this reaction is important in various fields, including environmental science and water treatment, as it influences pH levels in natural waters and can affect the solubility of minerals and gases.