## Chemistry: The Molecular Science (5th Edition)

This is an acid-base reaction: Acid: $H_2CO_3 (H_2O + CO_2)$ Base: $NH_3$
** Notice, the carbon dioxide and water are capable of forming carbonic acid: $CO_2 + H_2O -- \gt H_2CO_3$ And, when we add a base, like ammonia, this happens: $NH_3 + H_2CO_3 -- \gt NH_4HCO_3$ ** The carbonic acid gave an $H^+$ to the ammonia, so, this is an acid-base reaction.