Final answer:
In the reaction between Na2CO3(aq) and HNO3(aq), the NO3−(aq) ion is a spectator ion, which means it remains unchanged and does not participate in the reaction.
Step-by-step explanation:
The question asks about the identity of the spectator ion in the reaction between Na2CO3(aq) and HNO3(aq). A spectator ion is one that does not participate in the chemical reaction and remains unchanged in solution before and after the reaction occurs.
In this specific reaction, NO3−(aq) and Na+(aq) would be spectator ions as they do not participate in the overall chemistry of the reaction involving the carbonate CO32− and the hydrogen ion H+. Considering the options given, NO3−(aq) is a spectator ion.