When carbon dioxide mixes with water what does is form?

When carbon dioxide (CO2) mixes with water (H2O), it forms carbonic acid (H2CO3). This reaction occurs when CO2 dissolves in water, leading to a weak acid that can dissociate into bicarbonate (HCO3-) and hydrogen ions (H+). Carbonic acid plays a crucial role in regulating pH in natural water bodies and in biological systems.