Question

What are differences between `"Mohr's salt"`, and `"green vitriol"`?

Answer 1

Well, `"green vitriol"` is `Fe(SO)_4`, an iron(II) salt.........

Explanation:

And `"Mohr's salt"` is `(NH_4)_2[Fe(SO_4)_2] *6H_2O`.

And so in the solid state, they are different formulations.......and have different coordination geometry.

In solution, however, for both species, we LIKELY have `[Fe(OH_2)_6]^(2+)` as the dominant iron species in solution. The sulfate and ammonium counterions are along for the ride. There is possibly some literature on this, which is likely informed by `"UV-vis spectrometry"`.