MSO4nH2O

MSO4nH2O is a generic notation for a family of metal sulfate hydrates, where M denotes a metal cation and n indicates the number of water molecules of crystallization in the solid. The compound contains the sulfate group, SO4^2–, and the overall formula is often written as MSO4·nH2O. The value of n varies with the metal and the crystallization conditions, ranging from zero (anhydrous) to several water molecules.

In these hydrates, water molecules may be coordinated to the metal ion or reside in the crystal lattice. The hydration state influences properties such as solubility, stability, and crystal structure. Dehydration by heating or changes in humidity can convert MSO4·nH2O to MSO4·mH2O or to the anhydrous MSO4, often with accompanying changes in color and texture.

Common examples include magnesium sulfate heptahydrate (MgSO4·7H2O, known as Epsom salt), calcium sulfate dihydrate (CaSO4·2H2O, gypsum), and zinc sulfate heptahydrate (ZnSO4·7H2O). Each hydrate exhibits distinct physical properties and uses, reflecting the influence of the water of crystallization on the material's behavior.

Applications of MSO4 hydrates span chemical synthesis, agriculture, construction, and medicine. Hydrates serve as sources of metal ions in solutions, and their dehydration or hydration can be used to tailor solubility and reactivity. Safety considerations are in line with inorganic salts: handle powders to avoid inhalation, and observe standard laboratory procedures for moisture-sensitive materials.