[vmelkon]

Hello all,
if you have MgSO4 . 7H20 and you heat it, perhaps to 400 C, I guess the H20 gets released. I tried that experiment a long time ago and from what I remember, the MgSO4 became a white powder and for some reason it would no longer dissolve in water. Does MgSO4 decompose to perhaps MgO and gentle heating?

[Borek]

For decomposition you would need much higher temperature. I have never tried that in person, but my guess is that anhydrous magnesium sulfate is still soluble, it is just a very slow process.