Question

what type of reaction occures when a hydrochloric acid solution is mixed with a sodium bicarbonate solution?

I chose gas evolution, but am wondering if it is acid-base neutralization instead.

Answer 1

First, a double displacement (or double replacement).
HCl + NaHCO3 ==> NaCl + H2CO3.
Then a decomposition because H2CO3 is not stable at room temperature and atmospheric pressure.
H2CO3 ==> H2O + CO2.

Answer 2

so, my answers to choose from are gas evolution, precipitation, acid-base neutralization, and oxidation... I'm confused

Answer 3

Two of the answers are right. It is gas evolution (CO2 is produced) AND it is an acid/base neutralization. My best guess is that you are to pick gas evolution as the answer. Acid/base neutralization depends upon which definition you are using for acid and base. HCl is an acid by almost any definition one chooses; NaHCO3 is a base by the Bronsted-Lowry theory but not by the Arrhenius theory although I could make a case for it being a base by the Arrhenius theory if I tried.