Nitrocalcite: Difference between revisions

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|Trivial_Name        = Nitrate of lime
|Trivial_Name        = Nitrate of lime
|chemical_Formula      =Ca(NO<sub>3</sub>)<sub>2</sub>•4H<sub>2</sub>O  
|chemical_Formula      =Ca(NO<sub>3</sub>)<sub>2</sub>•4H<sub>2</sub>O  
|Hydratforms          =
|Hydratforms          =Ca(NO<sub>3</sub>)<sub>2</sub>•2H<sub>2</sub>O ([[calcium nitrate dihydrate]]) <br> Ca(NO<sub>3</sub>)<sub>2</sub>•3H<sub>2</sub>O ([[calcium nitrate trihydrate]])
|Crystal_System      =monoclinic
|Crystal_System      =monoclinic
|Crystal_Structure    =
|Crystal_Structure    =
|Deliqueszenzhumidity = 53.1% <bib id="Steiger etal: 2014"/>
|Deliqueszenzhumidity = 53.06%  
|Solubility          = 2660 g/l
|Solubility          = 7.726 mol/kg
|Density              = 1.82 g/cm<sup>3</sup>
|Density              = 1.82 g/cm<sup>3</sup>
|MolVolume            = 129.8 cm<sup>3</sup>/mol  
|MolVolume            = 129.8 cm<sup>3</sup>/mol  
|Molweight            = 236.16 g/mol  
|Molweight            = 236.15 g/mol  
|Transparency        = transparent
|Transparency        = transparent
|Cleavage            =
|Cleavage            =
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|chemBehavior        =
|chemBehavior        =
|Comments            =
|Comments            =
|Literature          =
|Literature          =<bib id="Steiger.etal:2014"/> <bib id="Broul.etal:1981"/>
}}
}}


back to [[Nitrate]]
back to [[Nitrate]]


== Phase Diagrams ==
== Solubility ==
[[file:CaN2 a.jpg|thumb|400px|left|'''Figure 1''' Phases in the system CaNO<sub>3</sub>/H<sub>2</sub>O (diagram: Michael Steiger)]]
[[file:Solubility of calcium nitrate in water.jpg|thumb|800px|left|'''Figure 1''' Solubility of calcium nitrate in water. The molality ''m'' [n(Ca(NO<sub>3</sub>)<sub>2</sub>•xH<sub>2</sub>O)•kg(H<sub>2</sub>O)<sup>-1</sup>] is plotted versus the temperature.]]  
[[file:Nikrocalcit T-Mol-klein.jpg|thumb|400px|left|'''Figure 2''' The system CaNO<sub>3</sub>/H<sub>2</sub>O between -30°C to 0°C (diagram : Michael Steiger)]]
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At 20 °C nitrocalcite is the stable phase of calcium nitrate. The salt has got a high solubilty in water and due to the temperature range of its stability it is relevant as a crystallizing phases under ambient conditions.
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==Hygroscopicity==


==Hygroscopicity==
[[file:Del Ca(NO3)2 e.jpg|thumb|800px|left|'''Figure 2''' Deliquescence behaviour of calcium nitrate. The water activity ''a<sub>w</sub>'' is plotted versus the temperature.]]


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Latest revision as of 07:58, 3 May 2023

Nitrocalcite[1]
HJS Ca(NO3)2 101703-10-1.jpg
Mineralogical name Nitrocalcite
Chemical name Calcium Nitrate Tetrahydrate
Trivial name Nitrate of lime
Chemical formula Ca(NO3)2•4H2O
Other forms Ca(NO3)2•2H2O (calcium nitrate dihydrate)
Ca(NO3)2•3H2O (calcium nitrate trihydrate)
Crystal system monoclinic
Crystal structure
Deliquescence humidity 20°C 53.06%
Solubility (g/l) at 20°C 7.726 mol/kg
Density (g/cm³) 1.82 g/cm3
Molar volume 129.8 cm3/mol
Molar weight 236.15 g/mol
Transparency transparent
Cleavage
Crystal habit
Twinning
Phase transition
Chemical behavior
Comments
Crystal Optics
Refractive Indices nx = 1.465
ny = 1.498
nz = 1.504
Birefringence Δ = 0.039
Optical Orientation negative
Pleochroism
Dispersion
Used Literature
[Steiger.etal:2014]Title: Weathering and Deterioration
Author: Steiger, Michael; Charola A. Elena; Sterflinger, Katja
Link to Google Scholar [Broul.etal:1981]Title: Solubility in organic two component systems
Author: Broul M., Nyvlt J.; Soehnel O.
Link to Google Scholar


back to Nitrate

Solubility[edit]

Figure 1 Solubility of calcium nitrate in water. The molality m [n(Ca(NO3)2•xH2O)•kg(H2O)-1] is plotted versus the temperature.




























At 20 °C nitrocalcite is the stable phase of calcium nitrate. The salt has got a high solubilty in water and due to the temperature range of its stability it is relevant as a crystallizing phases under ambient conditions.

Hygroscopicity[edit]

Figure 2 Deliquescence behaviour of calcium nitrate. The water activity aw is plotted versus the temperature.


Table 1: Deliquescence humidities of nitrocalcite at different round temperatures [Steiger.etal:2014]Title: Weathering and Deterioration
Author: Steiger, Michael; Charola A. Elena; Sterflinger, Katja
Link to Google Scholar
0°C 10°C 20°C 30°C 40°C 50°C
63.8%r.h. 58.8%r.h. 53.1%r.h. 46.0%r.h. 35.5%r.h. 21.3%r.h. (Ca(NO3)2•3H2O)


Under the polarizing microscope[edit]

  • Crystallized from a saturated solution with ethanol addition
  • in simple polarized light

    in simple polarized light

  • under crossed polarizers

    under crossed polarizers

  • under crossed polarizers and Red I

    under crossed polarizers and Red I

Weblinks
[edit]

  1. ↑ http://www.mindat.org/min-2919.html seen on 29.07.2010

Literature[edit]

[Broul.etal:1981]Elsevier (eds.) Broul M., Nyvlt J.; Soehnel O. (1981): Solubility in organic two component systems, ElsevierLink to Google Scholar
[Steiger.etal:2014]Steiger, Michael; Charola A. Elena; Sterflinger, Katja (2014): Weathering and Deterioration. In: Siegesmund S.; Snethlage R. (eds.): Stone in Architecture, Springer Verlag Berlin Heidelberg, 223-316, 10.1007/978-3-642-45155-3_4.Link to Google Scholar

A phase is a physically distinctive form of matter and is characterized by having relatively uniform chemical and physical properties.

concentration given as amount of substance (mol) of the dissolved substance per kilogram solvent; unit: mol•kg-1.

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