You are analyzing a solid isolated from a reaction and find that its boiling point is over 1000 ∘C. You dissolve the compound in water solution and recrystallize it to produce some solid crystals that you use to determine that the compound is a crystalline solid. Which of the following could be the identity of the unknown solid?

Phosphorus tribromide PBr3
Silicon carbide SiC
Sodium iodide NaI
Iron (II) chloride FeCl2
thank you

The answer is NaI & FeCl2.

There are actually 2 answers to this question. So, you don't have to pick just one.

Both NaI and FeCl2 boil above 1000 C but FeCl2 is difficult (if not impossible) to recrystallize from H2O; therefore, I would go with NaI.

Beryllium Fluoride BeF2

Magnesium Chloride MgCI2

Fecl2 and Bef2

sodium iodide

MgCl2

Silicon carbide SiC