Magnesium(II) sulfate hydrates | SSHADE

Solid phase

Official name: Magnesium(II) sulfate hydrates

Name and identifiers

Secondary names: Magnesium sulphate hydrates

Family: ionic solid
Class: normal salt
Compound type: sulfate
Comments: Magnesium sulfate hydrates occurs as minerals: Kieserite (monohydrate), Starkeyite (tetrahydrate), Pentahydrite (pentahydrate), Hexahydrite (hexahydrate), Epsomite (heptahydrate) and Meridianite (undecahydrate).

Phase diagram of

M g S O_{4}

$MgSO_4$ hydrates

Chemical composition

Formula: $Mg^{2+} \cdot SO_4^{2-} \bullet nH_2O$
Chemical formula: MgSO4•nH2O
Elemental formula: (Mg2+) S (O)3-13 (O-)2 (H)2-22
Isotope mixture type: terrestrial abundance

16.0

	Formula	Name	Family	Number min-max	Mole fraction	Isotope mole fraction	State	Relevance
	$Mg^{2+}$	Magnesium(II) cation	element	1	0.125	1	constituent cation	main
	$(SO_4)^{2-}$	Sulfate anion	chemical function	1	0.125	1	anionic radical	main
	$H_2O$	Water	molecule	1 - 11	0.75 $\pm$ 0.625	1	hydration	main

Composition comments: the is a dozen of different hydrates with hydration number between 1 and 11

Chemical functions and bonds

Chemical functions

	Function	Number
	$(SO_4)^{2-}$	1
	$R-OH$	2

Chemical bonds

	Bond	Number
	$\cdot Mg^{2+} \cdot O^{-}-$	2
	$-O \dots H-$	2n
	$-O-H$	2
	$\dddot - \dddot - \dddot - S \dddot - O^{-1/2}$	4

Class: normal salts (07)
Type: hydrated simple normal salts (07.04)

Endmembers and polymorphs

Endmembers

Crystallography

Phase type: crystalline
Crystal system: various
Crystal class: various
Crystal class symbol: various
Crystal spacegroup: various
Comments: The structure depends on degree of hydration

Physical properties

Molar mass: 138.38 (n=1) - 336.545 (n=11) $g/mol$
Density: 2.445 (n=1) - 1.512 (n=11) $g/cm^3$

Thermodynamical properties

State NTP: solid

Optical properties

Refringence type: various
Pure color: colorless
Color: colorless
Diaphaneity: transparent to translucent
Luster: vitreous

Links and Publications

Links

Wikipedia: Magnesium Sulfate