Strontium sulfate

{{#if:183.68 g/molwhite orthorhombic crystalsSrSO₄3.44 x 10^-73.96 g/cm³1606°C0.0135 g/100 mL (25 °C)
0.014 g/100 mL (30 °C)insoluble in ethanol, alkalis
slightly soluble in acids1.622 |! style="background: #F8EABA; text-align: center;" colspan="2" | Properties

Strontium sulfate
File:Barite-unit-cell-3D-vdW.png
IUPAC name Strontium sulfate
Other names Celestine
Identifiers
CAS number	7759-02-6 7pxY
PubChem	3084026
ChemSpider	2341151 7pxY
Jmol-3D images	Image 1
SMILES [Sr+2].[O-]S([O-])(=O)=O <p><p style="word-wrap: break-word;">
InChI InChI=1S/H2O4S.Sr/c1-5(2,3)4;/h(H2,1,2,3,4);/q;+2/p-2 7pxY Key: UBXAKNTVXQMEAG-UHFFFAOYSA-L 7pxY InChI=1/H2O4S.Sr/c1-5(2,3)4;/h(H2,1,2,3,4);/q;+2/p-2 Key: UBXAKNTVXQMEAG-NUQVWONBAV
Molecular formula	SrSO4
Molar mass	183.68 g/mol
Appearance	white orthorhombic crystals
Density	3.96 g/cm3
Melting point	1606°C
Solubility in water	0.0135 g/100 mL (25 °C) 0.014 g/100 mL (30 °C)
Solubility product, Ksp	3.44 x 10-7
Solubility	insoluble in ethanol, alkalis slightly soluble in acids
Refractive index (nD)	1.622
Structure
Crystal structure	Orthorhombic, oP24
Space group	Pnma, No. 62
Thermochemistry
Std enthalpy of formation ΔfHo298	-1453.1 kJ·mol-1
Standard molar entropy So298	117.0 J·mol-1·K-1
Hazards
MSDS	External MSDS data	EU Index	Not listed
Flash point	Non-flammable
Related compounds
Other anions	Strontium chloride Strontium oxide
Other cations	Beryllium sulfate Magnesium sulfate Calcium sulfate Barium sulfate
14pxY (verify) (what is: 10pxY/10pxN?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Strontium sulfate (SrSO₄) is the sulfate salt of strontium. It is a white crystalline powder and occurs in nature as the mineral celestine. It is poorly soluble in water to the extent of 1 part in 8,800. It is more soluble in dilute HCl and nitric acid and appreciably soluble in alkali chloride solutions (e.g. sodium chloride).

Structure

Strontium sulfate is a polymeric material, isostructural with barium sulfate. Crystallized strontium sulfate is utilized by a small group of radiolarian protozoa, called the Acantharea, as a main constituent of their skeleton.

Applications

Strontium sulfate is of interest as a naturally occurring precursor to other strontium compounds, which are more useful. In industry it is converted to the carbonate for use as ceramic precursor and the nitrate for use in pyrotechnics.

SrSO₄ Scale in Oilfield

SrSO₄ scale is typically only a problem in water-flooded fields because the strontium in the formation water can mix with the sulphate in the injected seawater and drop out SrSO₄ scale as they are mixed in the producing wells. It is less a problem in non-water-flooded fields because its formation kinetics is typically slow (unless the temperature is very high, >100C)and the sulphate is typically taken up by barium to form barium sulfate, which has a much faster kinetics.