To solve this problem, we need to know the cation and anion for each formula and the symbol for each name.
17. Nickel (II) sulfide
Ni^2+ S^2-
Formula: NiS
18. lead (IV) bromide
Pb^4+ Br^-
PbBr4
19. Strontium nitride
Sr^2+ N^3-
Sr3N2
20. lead (II) nitride
Pb^2+ N^3-
Pb3N2
21. iron (III) oxide
Fe^3+ O^2-
Fe2O3
22. Iron (II) iodide
Fe^2+ I^-
FeI2
23. Tin (IV) phosphide
Sn^4+ P ^3-
Sn3P4
24. Silver phosphide
Ag^+ P^3-
Ag3P
25. Copper (I) sulfide
Cu^+ S^2-
Cu2S