Final answer:
The reaction Li3N + 3NH4NO3 → 3LiNO3 + (NH4)3N does not involve changes in oxidation numbers; hence, it is not a redox reaction but a double-replacement reaction.
Step-by-step explanation:
To determine whether the reaction Li3N + 3NH4NO3 → 3LiNO3 + (NH4)3N is a redox reaction or not, we need to examine changes in oxidation numbers of the elements involved in the reaction. In redox reactions, there must be a change in oxidation number indicative of the transfer of electrons. However, in this reaction, the nitrogen and lithium ions switch partners, but there is no actual change in the oxidation numbers for any element. This is characteristic of a double-replacement reaction, where two compounds exchange parts, generally without any change in oxidation states. Therefore, since there are no changes in oxidation numbers, this reaction is not a redox reaction.
Answer: C. The reaction is not a redox reaction because it does not include any oxidation number changes.