[steven8gerrard]

Will the water of crystallization dissolve/separated in water and turn back to liquid water?
i think it may be separated in the light of Fe2O3 . n H2O -->Fe2O3+nH2O....

[Borek]

Depends. Sometimes it will, but in some salts water molecules are ligands complexing the metal ion - so they will stay attached to the metal.

[steven8gerrard]

isee thanks!! Btw,, will the water of crystallization of ethanedioic acid (COOH)2·2H2O,CuSO4·5H2O be separated when they dissolve in water respectively?

[Borek]

In the case of oxalic acid yes, water will land in the solution. Copper sulfate is more complicated, as of these 5 water  molecules 4 are directly bonded to the copper ion, fifth is not, but on dissolution copper gets complexed by additional two water molecules creating hexaaquacopper(II) ion, so in fact it "removes" one water molecules from the solution.

At least that's how I remember it.

[steven8gerrard]

thank you very much !!!!