# How do you write the chemical equation for the reaction of carbonic acid (H_2CO_3) with water?

H_2CO_3(aq) +H_2O(l) rarr H_3O^(+) + ""^(-)O(O=)C-OH
$\text{Carbonic acid "rarr" bicarbonate ion}$
Most of the time we can treat carbonic acid, ${H}_{2} C {O}_{3}$, as hydrated carbon dioxide: i.e. ${H}_{2} C {O}_{3} \equiv {\left(O =\right)}_{2} C \cdot {H}_{2} O$. The oxidation states are the same.