When the following two solutions are mixed:
K2CO3(aq) + Fe(NO3)3(aq)
the mixture contains the ions listed below.
1. Sort these species into spectator ions and ions that react.
O NO3^-(aq)
O Fe^3+(aq)
O CO3^2-(aq)
O K+(aq)

the two spectator ions are;  K(+) and NO3(-)

Explanation:

First off, let's write out the balanced chemical equation for the reaction;

3K2CO3(aq) +2Fe(NO3)3(aq) > 6KNO3(aq) + Fe2(CO3)3(s)

In order to identify which ions are spectators, we have to break the equation down to an ionic equation. This is done by splitting all aqueous compounds into ions while leaving the solids, liquids as they are.

We have;

K(+) + CO3(2-) + Fe(3+) + NO3(-) ---> K(+) + NO3(-) + Fe2(CO3)3(s)

Spectators ions are pretty much those ions that do not undergo a change in the reaction. Spectator ions always have the same number of moles and charge in both sides of the reaction.

Upon observing the ionic equation, we can tell that the two spectator ions are;  K(+) and NO3(-)