I need to understand how to make a net ionic equation using the following elements:

Question

Sr++, Hg2, NaCl

Or these: NH4, Ca++, K2SO4

I was not given the products of the reactions.

Answer 1

I think the idea here is to be able to recognize which of the ions in the set will react. In the first set. Hg2Cl2 is an insoluble compound (a precipitate).
Hg2^+2(aq) + 2Cl^-(aq) ==> Hg2Cl2(s)

In the second set, CaSO4 is insoluble.
Ca^+2(aq) + SO4^-2(aq) ==> CaSO4(s)