Sodium sulfate phase III

Author: Amelie Stahlbuhk
back to Sulfate

Sodium sulfate phase III

Mineralogical name
Chemical name	sodium sulfate phase III
Trivial name
Chemical formula	Na₂SO₄
Other forms	Na₂SO₄•10H₂O (Mirabilite) Na₂SO₄•7H₂O (Sodium sulfate heptahydrate)
Crystal system
Crystal structure
Deliquescence humidity 20°C	82.9 %
Solubility (g/l) at 20°C	4.428 mol/kg
Density (g/cm³)
Molar volume
Molar weight	142.04 g/mol
Transparency
Cleavage
Crystal habit
Twinning
Phase transition
Chemical behavior
Comments
Crystal Optics
Refractive Indices
Birefringence
Optical Orientation
Pleochroism
Dispersion
Used Literature
[Steiger.etal:2008]Author: Steiger, Michael; Asmussen, Sönke Journal: Geochimica et Cosmochimica Acta Number: 17 Pages: 4291-4306 Title: Crystallization of sodium sulfate phases in porous materials: The phase diagram Na2SO4–H2O and the generation of stress Volume: 72 Year: 2008

Abstract

Sodium sulfate phase III as a metastable and anhydrous phase of sodium sulfate and its properties are presented.

Occurence

The phase was observed next to thenardite during the evaporation of sodium sulfate solutions above 32.4 °C which is above the transition temperature of mirabilite to thenardite. The amount of metastable phase III increases with increasing temperature [Amirthalingam.etal:1977]Author: Amirthalingam V., Karkhanavala M. D., Rao U. R. K.
Journal: Acta Cryst.
Note: Band A33
Pages: 522
Title: Topotaxic phase change in Na2SO4
Year: 1977
, [Grossi.etal:1997]Author: Grossi, C.M.; Esbert, R.M.; Suarez del Rio, L.M.; Montoto, M.; Laurenzi-Tabasso, M.
Journal: Studies in Conservation
Number: 2
Pages: 115-125
Title: Acoustic emmission monitoring to study sodium sulphate crystallization in monumental porous carbonate stones
Year: 1997
.
In addition the phase was detected during evaporation tests with sodium sulfate solutions at room temperature and low relative humidity [Linnow.etal:2006]Author: Linnow, Kirsten; Zeunert, Anke; Steiger, Michael
Journal: Analytical Chemistry
Number: 13
Pages: 4683-4689
Title: Investigation of Sodium Sulfate Phase Transitions in a Porous Material Using Humidity- and Temperature-Controlled X-ray Diffraction
Volume: 78
Year: 2006
, [Xu.etal:1999]Author: Xu B., Schweiger G.
Journal: J. Aerosol. Sci.
Note: Band 30 (Suppl.)
Pages: 379-380
Title: In-situ Raman observations of phase transformation of Na2SO4 during the hydration/dehydration cycles on single levitated microparticle.
Year: 1999
, [Rodriguez-Navarro.etal:1999]Author: Rodriguez-Navarro, Carlos; Doehne, Eric
Journal: Cement and Concrete Research
Pages: 1527-1534
Title: How does sodium sulphate crystallize?
Url: http://hera.ugr.es/doi/14997496.pdf
Volume: 30
Year: 2000
.

Solubility

Figure 1: Solubility of Na₂SO₄ in water, according to : [Steiger.etal:2008]Author: Steiger, Michael; Asmussen, Sönke
Journal: Geochimica et Cosmochimica Acta
Number: 17
Pages: 4291-4306
Title: Crystallization of sodium sulfate phases in porous materials: The phase diagram Na2SO4–H2O and the generation of stress
Volume: 72
Year: 2008

With a solubility of 4.4 mol/kg at 20 °C [Steiger.etal:2008]Author: Steiger, Michael; Asmussen, Sönke
Journal: Geochimica et Cosmochimica Acta
Number: 17
Pages: 4291-4306
Title: Crystallization of sodium sulfate phases in porous materials: The phase diagram Na2SO4–H2O and the generation of stress
Volume: 72
Year: 2008
phase III has got a higher solubility than the other phases of the system Na₂SO₄-H₂O (see also sodium sulfate).

Hygroscopicity

Figure 2:Deliquescence of Na₂SO₄, according to: [Steiger.etal:2008]Author: Steiger, Michael; Asmussen, Sönke
Journal: Geochimica et Cosmochimica Acta
Number: 17
Pages: 4291-4306
Title: Crystallization of sodium sulfate phases in porous materials: The phase diagram Na2SO4–H2O and the generation of stress
Volume: 72
Year: 2008

The deliquescence humidity of phase III at 20 °C is 82.9 % and it slowly increases with increasing temperature.

Table 1: Deliquescence humidity of sodium sulfate phase III at different round temperatures, according to [Steiger.etal:2008]**Author:** *Steiger, Michael; Asmussen, Sönke*
**Journal:** *Geochimica et Cosmochimica Acta*
**Number:** 17
**Pages:** *4291-4306*
**Title:** *Crystallization of sodium sulfate phases in porous materials: The phase diagram Na2SO4–H2O and the generation of stress*
**Volume:** 72
**Year:** *2008*
0°C	10°C	20°C	30°C	40°C	50°C
79.9%r.h.	81.6%r.h.	82.9%r.h.	84.0%r.h.	84.9%r.h.	85.7%r.h.

Weblinks

Literatur

[Amirthalingam.etal:1977]	Amirthalingam V., Karkhanavala M. D., Rao U. R. K. (1977): Topotaxic phase change in Na2SO4. Acta Cryst., %volume% (%number%), 522, %url%, %doi%
[Grossi.etal:1997]	Grossi, C.M.; Esbert, R.M.; Suarez del Rio, L.M.; Montoto, M.; Laurenzi-Tabasso, M. (1997): Acoustic emmission monitoring to study sodium sulphate crystallization in monumental porous carbonate stones. Studies in Conservation, %volume% (2), 115-125, %url%, %doi%
[Linnow.etal:2006]	Linnow, Kirsten; Zeunert, Anke; Steiger, Michael (2006): Investigation of Sodium Sulfate Phase Transitions in a Porous Material Using Humidity- and Temperature-Controlled X-ray Diffraction. Analytical Chemistry, 78 (13), 4683-4689, %url%, 10.1021/ac0603936
[Rodriguez-Navarro.etal:1999]	Rodriguez-Navarro, Carlos; Doehne, Eric (2000): How does sodium sulphate crystallize?. Cement and Concrete Research, 30 (%number%), 1527-1534, Url, 10.1016/S0008-8846(00)00381-1
[Steiger.etal:2008]	Steiger, Michael; Asmussen, Sönke (2008): Crystallization of sodium sulfate phases in porous materials: The phase diagram Na2SO4–H2O and the generation of stress. Geochimica et Cosmochimica Acta, 72 (17), 4291-4306, %url%, 10.1016/j.gca.2008.05.053
[Xu.etal:1999]	Xu B., Schweiger G. (1999): In-situ Raman observations of phase transformation of Na2SO4 during the hydration/dehydration cycles on single levitated microparticle.. J. Aerosol. Sci., %volume% (%number%), 379-380, %url%, %doi%