Final answer:
A precipitation reaction occurs when aqueous solutions of sodium sulfide and iron(II) sulfate are combined, forming insoluble iron(II) sulfide represented by the net ionic equation Fe²+ (aq) + S²- (aq) → FeS (s).
Step-by-step explanation:
When aqueous solutions of sodium sulfide and iron(II) sulfate are combined, a precipitation reaction occurs because iron(II) sulfide is insoluble in water. To write the net ionic equation, you need to consider the ions that actually participate in the reaction. The net ionic equation for this reaction is:
Fe²+ (aq) + S²- (aq) → FeS (s)