What is the ionic equation when two ionic compounds mix together to create a precipitate?

Question

If no precipitate forms, then the equasion is unnessary; just state that no precipitate formed.

1. Ca(NO3)2(aq) and Na2S(aq)
2. Na3PO4(aq) and Pb(NO3)2(aq)
3. FeCl3(aq) and NH4NO3(aq)

Answer 1

Ca+2 + S= ===> CaS(s)

2PO4 3- + 3Pb2+ ===> Pb3(PO4)2(s)

3. No precipitate forms.