Solid phase
Official name
Magnesium(II) sulfate pentahydrate
Secondary names
Magnesium sulphate pentahydrate
CAS number
15553-21-6
Type
Family
ionic solid
Class
normal salt
Compound type
sulfate
Comments
Magnesium sulfate pentahydrate occurs as a mineral: Pentahydrite
Chemical composition
Formula
$Mg^{2+} \cdot SO_4^{2-} \bullet 5H_2O$
Chemical formula
MgSO4•5H2O
Elemental formula
(Mg2+) S O7 (O-)2 H10
Isotope mixture type
terrestrial abundance
14.0
  Formula Name Family Number min-max Mole fraction Isotope mole fraction State Relevance
$Mg^{2+}$ Magnesium(II) cation element 1 0.14285714285714285 1 constituent cation main
$(SO_4)^{2-}$ Sulfate anion chemical function 1 0.14285714285714285 1 anionic radical main
$H_2O$ Water molecule 5 0.7142857142857143 1 hydration main
Chemical functions
  Function Number
$(SO_4)^{2-}$ 1
$R-OH$ 2
Chemical bonds
  Bond Number
$\cdot Mg^{2+} \cdot O^{-}-$ 2
$-O \dots H-$ 10
$-O-H$ 2
$\dddot - \dddot - \dddot - S \dddot - O^{-1/2}$ 4
Class
normal salts (07)
Type
hydrated simple normal salts (07.04)
Equivalent mineral
Pentahydrite
Phase type
crystalline
Crystal system
triclinic
Crystal class
pinacoidal
Crystal class symbol
-1 (Ci)
Crystal spacegroup
P-1
Molar mass
210.45 $g/mol$
Density
1.9 $g/cm^3$
State NTP
solid
Refringence type
biaxial
Refringence sign
negative
Birefringence
0.011
Refraction index $n_{\alpha}$
1.482
Refraction index $n_{\beta}$
1.492
Refraction index $n_{\gamma}$
1.493
Pure color
colorless
Color
colorless, white
Diaphaneity
transparent to translucent
Luster
vitreous
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