The product formed when sodium trioxocarbonate(IV) (also known as sodium carbonate, Na₂CO₃) reacts with aqueous hydrochloric acid (HCl) is:

* Sodium chloride (NaCl)

* Carbon dioxide (CO₂) gas

* Water (H₂O)

Here's the balanced chemical equation for the reaction:

Na₂CO₃(s) + 2HCl(aq) → 2NaCl(aq) + CO₂(g) + H₂O(l)

This reaction is a classic example of an acid-base reaction, where the carbonate ion (CO₃²⁻) acts as a base and reacts with the hydrogen ions (H⁺) from the hydrochloric acid to form carbonic acid (H₂CO₃). Carbonic acid is unstable and quickly decomposes into carbon dioxide and water.