Magnesium sulfate

This article is about the chemical compound. For medical uses, see Magnesium sulfate (medical use).

Magnesium sulfate

Magnesium sulfate hexahydrate

Anhydrous magnesium sulfate

Epsomite (Magnesium sulfate heptahydrate)
Names
IUPAC name
Magnesium sulfate
Other names
  • Epsom salt (Magnesium sulfate heptahydrate)
  • English salt
  • Bitter salts
  • Bath salt
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
DrugBank
ECHA InfoCard 100.028.453 Edit this at Wikidata
EC Number
  • 231-298-2
KEGG
RTECS number
  • OM4500000
UNII
  • InChI=1S/Mg.H2O4S/c;1-5(2,3)4/h;(H2,1,2,3,4)/q+2;/p-2 checkY
    Key: CSNNHWWHGAXBCP-UHFFFAOYSA-L checkY
  • InChI=1/Mg.8H2O4S/c;1-5(2,3)4/h;(H2,1,2,3,4)/q+2;/p-2
    Key: CSNNHWWHGAXBCP-NUQVWONBAQ
  • [Mg+2].[O-]S([O-])(=O)=O
Properties
MgSO4
Molar mass
  • 120.366 g/mol (anhydrous)
  • 138.38 g/mol (monohydrate)
  • 174.41 g/mol (trihydrate)
  • 210.44 g/mol (pentahydrate)
  • 228.46 g/mol (hexahydrate)
  • 246.47 g/mol (heptahydrate)
Appearance white crystalline solid
Odor odorless
Density
  • 2.66 g/cm3 (anhydrous)
  • 2.445 g/cm3 (monohydrate)
  • 1.68 g/cm3 (heptahydrate)
  • 1.512 g/cm3 (undecahydrate)
Melting point
  • anhydrous decomposes at 1,124 °C
  • monohydrate decomposes at 200 °C
  • heptahydrate decomposes at 150 °C
  • undecahydrate decomposes at 2 °C
  • anhydrous
  • 26.9 g/(100 mL) (0 °C)
  • 35.1 g/(100 mL) (20 °C)
  • 50.2 g/(100 mL) (100 °C)
  • heptahydrate
  • 113 g/(100 mL) (20 °C)
738 (502 g/L)
Solubility
−50·10−6 cm3/mol
1.523 (monohydrate)
1.433 (heptahydrate)
Structure
monoclinic (hydrate)
Pharmacology
A06AD04 (WHO) A12CC02 (WHO) B05XA05 (WHO) D11AX05 (WHO) V04CC02 (WHO)
Hazards
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
1
0
0
Related compounds
Other cations
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

Magnesium sulfate or magnesium sulphate is a chemical compound, a salt with the formula MgSO4, consisting of magnesium cations Mg2+ (20.19% by mass) and sulfate anions SO2−4. It is a white crystalline solid, soluble in water but not in ethanol.

Magnesium sulfate is usually encountered in the form of a hydrate MgSO4·nH2O, for various values of n between 1 and 11. The most common is the heptahydrate MgSO4·7H2O,[1] known as Epsom salt, which is a household chemical with many traditional uses, including bath salts.[2]

The main use of magnesium sulfate is in agriculture, to correct soils deficient in magnesium (an essential plant nutrient because of the role of magnesium in chlorophyll and photosynthesis). The monohydrate is favored for this use; by the mid 1970s, its production was 2.3 million tons per year.[3] The anhydrous form and several hydrates occur in nature as minerals, and the salt is a significant component of the water from some springs.

  1. ^ Connor, Nick (24 July 2023). "Magnesium Sulfate | Formula, Properties & Application". Material Properties. Retrieved 4 February 2024.
  2. ^ Cite error: The named reference wsjdXXXX was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference buch2000 was invoked but never defined (see the help page).