Answer:
FeCl: Ferric Chloride (also called iron chloride), comes from Fe (ferrum, or iron), and Cl (Chlorine)
HNO: Nitroxyl, from N (Nitrogen), and the acidic nature of a radical ending in -yl.
NaSO: Sodium sulfate, Na (Sodium), S (Sulfur), O (Oxygen).
SO: Sulfur monoxide (Mono-One), O (Oxygen) and S (Sulfur).