What is formed when carbon dioxide reacts with water?

When carbon dioxide reacts with water, carbonic acid is formed through the following chemical reaction:

[ CO_2(g) + H_2O(l) \rightleftharpoons H_2CO_3(aq) ]

In this reaction, carbon dioxide dissolves in water and reacts to create carbonic acid (H₂CO₃). Carbonic acid is a weak acid that can dissociate partially in solution, contributing to the acidity of rainwater and playing a significant role in the carbon cycle as well as biological processes.

The other acids mentioned in the options do not form as a result of the reaction between carbon dioxide and water. Hydrochloric acid, nitric acid, and sulfuric acid are strong acids that result from different chemical reactions involving their respective precursors, but they are not produced from the interaction of carbon dioxide with water. Thus, understanding the specific products of chemical reactions is crucial in aqueous chemistry, highlighting the importance of carbonic acid in both environmental and biological contexts.