View source for Calcium nitrate

{{chembox
| Verifiedfields = changed
| Watchedfields  = changed
| verifiedrevid  = 477003207
| Name           = Calcium nitrate
| ImageFile      = calcium nitrate.png
| ImageFile1     = Calcium-nitrate-3D-vdW.png
| ImageSize      = 150px
| ImageFile2     = Dusičnan vápenatý.JPG
| ImageSize2     = 220px
| ImageName      = picture of constituent ions
| IUPACName      = 
| OtherNames     = Kalksalpeter, Norgessalpeter, nitrocalcite, Norwegian salpeter, lime nitrate
| SystematicName = 
| Section1       = {{Chembox Identifiers
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 23336
| InChI = 1/Ca.2NO3/c;2*2-1(3)4/q+2;2*-1
| SMILES = [Ca+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O
| InChIKey = ZCCIPPOKBCJFDN-UHFFFAOYAF
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/Ca.2NO3/c;2*2-1(3)4/q+2;2*-1
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = ZCCIPPOKBCJFDN-UHFFFAOYSA-N
| CASNo = 10124-37-5 
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo2_Ref = {{cascite|correct|CAS}}
| CASNo2 = 13477-34-4
| CASNo2_Comment = (tetrahydrate)
| EC_number = 233-332-1
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = NF52F38N1N
| UNII1_Ref = {{fdacite|correct|FDA}}
| UNII1 = O8T8H4NBBR
| UNII1_Comment = (tetrahydrate)
| ChEBI = 64205
| ChEMBL = 3183960
| PubChem = 24963
| RTECS = EW2985000
| UNNumber = 1454
  }}
| Section2       = {{Chembox Properties
| Formula = Ca(NO<sub>3</sub>)<sub>2</sub>
| MolarMass = 164.088 g/mol (anhydrous) <br/> 236.15 g/mol (tetrahydrate)
| Appearance = colorless solid <br/> [[hygroscopic]]
| Density = 2.504 g/cm<sup>3</sup> (anhydrous)<br/>1.896 g/cm<sup>3</sup> (tetrahydrate)
| Solubility = ''anhydrous:'' <br/> 1212 g/L (20&nbsp;°C) <br/> 2710 g/L (40&nbsp;°C) <hr/> ''tetrahydrate:'' <br/> 1050 g/L (0&nbsp;°C) <br/> 1290 g/L (20&nbsp;°C) <br/> 3630 g/L (100&nbsp;°C)
| Solubility1 = 51.4 g/100 g (20&nbsp;°C)<br/> 62.9 g/100 g (40&nbsp;°C)<ref name=chemister>{{cite web|last = Anatolievich|first = Kiper Ruslan|url = http://chemister.ru/Database/properties-en.php?dbid=1&id=558|title = Properties of substance: calcium nitrate|access-date = 2015-09-09}}</ref>
| Solvent1 = ethanol
| Solubility2 = 134 g/100 g (10&nbsp;°C)<br/> 144 g/100 g (40&nbsp;°C)<br/> 158 g/100 g (60&nbsp;°C)<ref name=chemister />
| Solvent2 = methanol
| Solubility3 = 33.08 g/100g (anhydrous, 25&nbsp;°C)<ref>{{cite journal |title=Application of Infrared Spectroscopy to the Analysis of Inorganic Nitrates |journal=Defense Technical Information Centre |date=1968-05-01 |last=Norwitz |first=George |last2=Chasan |first2=David E. |url=https://apps.dtic.mil/sti/pdfs/AD0673124.pdf |format=PDF |accessdate=2023-01-21 }}</ref>
| Solvent3 = acetone
| SolubleOther = soluble in [[ammonia]] <br/> almost insoluble in [[nitric acid]]
| MeltingPtC = 561
| MeltingPt_notes = (anhydrous)<br/> 42.7&nbsp;°C (109 °F; 316 K) (tetrahydrate)
| BoilingPt = decomposes (anhydrous) <br/> 132&nbsp;°C (270 °F; 405 K) (tetrahydrate)
| pKa = 6.0
| MagSus = −45.9·10<sup>−6</sup> cm<sup>3</sup>/mol
  }}
| Section3       = {{Chembox Structure
| Coordination = 
| CrystalStruct = cubic (anhydrous)<br/>monoclinic (tetrahydrate)
  }}
| Section4       = 
| Section5       = 
| Section6       = 
| Section7       = {{Chembox Hazards
| ExternalSDS = [http://www.inchem.org/documents/icsc/icsc/eics1037.htm ICSC 1037]
| GHSPictograms = {{GHS03}}{{GHS05}}{{GHS07}}
| GHSSignalWord = Danger
| HPhrases = {{H-phrases|272|302|315|319}}
| PPhrases = {{P-phrases|210|220|221|264|270|280|301+312|302+352|305+351+338|310|321|330|332+313|337+313|362|370+378|501}}
| NFPA-H = 2
| NFPA-F = 0
| NFPA-R = 1
| NFPA-S = OX
| FlashPt = Non-flammable
| LD50 = 302 mg/kg (rat, oral)
  }}
| Section8       = {{Chembox Related
| OtherAnions = [[Calcium sulfate]]<br/>[[Calcium chloride]]
| OtherCations = [[Magnesium nitrate]]<br/>[[Strontium nitrate]]<br/>[[Barium nitrate]]
  }}
}}
'''Calcium nitrate''' are [[inorganic compound]]s with the formula Ca(NO<sub>3</sub>)<sub>2</sub>(H<sub>2</sub>O)<sub>x</sub>. The anhydrous compound, which is rarely encountered, [[Hygroscopy|absorbs moisture]] from the air to give the [[water of crystallization|tetrahydrate]]. Both anhydrous and hydrated forms are colourless [[Salt (chemistry)|salt]]s. Hydrated calcium nitrate, also called ''Norgessalpeter'' ('''Norwegian salpeter'''), is mainly used as a component in [[fertilizer]]s, but it has other applications. '''Nitrocalcite''' is the name for a mineral which is a hydrated calcium nitrate that forms as an [[efflorescence]] where [[manure]] contacts [[concrete]] or [[limestone]] in a dry environment as in stables or [[caverns]]. A variety of related salts are known including calcium [[ammonium nitrate]] decahydrate and calcium [[potassium nitrate]] decahydrate.<ref name=Ullmann>{{Ullmann|Wolfgang Laue, Michael Thiemann, Erich Scheibler, Karl Wilhelm Wiegand|title=Nitrates and Nitrites|year=2002|doi=10.1002/14356007.a17_265}}</ref>

==Production and reactivity==
Norgessalpeter was synthesized at [[Notodden]], [[Norway]] in 1905 by the [[Birkeland–Eyde process]]. Most of the world's calcium nitrate is now made in [[Porsgrunn]]. It is produced by treating limestone with [[nitric acid]], followed by neutralization with ammonia:
:{{chem2|CaCO3 + 2 HNO3 -> Ca(NO3)2 + CO2 + H2O}}

It is also an intermediate product of the [[Nitrophosphate process|Odda Process]]:
:{{chem2|Ca5(PO4)3OH + 10 HNO3 -> 3 H3PO4 + 5 Ca(NO3)2 + H2O}}

It can also be prepared from an aqueous solution of [[ammonium nitrate]], and [[calcium hydroxide]]:
:{{chem2|2 NH4NO3 + Ca(OH)2 -> Ca(NO3)2 + 2 NH4OH}}

Like related [[alkaline earth metal]] nitrates, calcium nitrate decomposes upon heating (starting at 500&nbsp;°C) to release [[nitrogen dioxide]]:<ref name=Ullmann/>
:{{chem2|2 Ca(NO3)2 -> 2 CaO + 4 NO2 + O2}}   ΔH = 369 kJ/mol

==Applications==

===Use in agriculture===
The fertilizer grade (15.5-0-0 + 19% Ca) is popular in the [[greenhouse]] and [[hydroponics]] trades; it contains [[ammonium nitrate]] and [[water]], as the "double salt" {{chem2|5Ca(NO3)2*NH4NO3*10H2O}}. This is called [[calcium ammonium nitrate]] and often the name calcium nitrate prill is used as it always comes in a prilled (granular) form. Formulations lacking ammonia are also known: {{chem2|Ca(NO3)2*4H2O}} (11.9-0-0 + 16.9 Ca) and the water-free 17-0-0 + 23.6 Ca. A liquid formulation (9-0-0 + 11 Ca) is also offered. An [[anhydrous]], air-stable derivative is the urea [[coordination complex|complex]] {{chem2|Ca(NO3)2*4[OC(NH2)2]}}, which has been sold as Cal-Urea.

Calcium nitrate is also used to control certain plant diseases. For example, dilute calcium nitrate (and [[calcium chloride]]) sprays are used to control bitter pit and cork spot in apple trees.<ref>{{cite web|title=Bitter Pit and Cork Spot|url=https://hort.uwex.edu/articles/bitter-pit-and-cork-spot/|website=University of Wisconsin-Extension Cooperative Extension|publisher=UW-Madison, Dept of Horticulture}}</ref>

===Waste water treatment===
[[File:Calcium nitrate, waste water treatment.jpg|thumb|left|150px|Waste water treatment unit]]
Calcium nitrate is used in waste water pre-conditioning for odour emission prevention. The waste water pre-conditioning is based on establishing an anoxic biology in the waste water system. In the presence of nitrate, the metabolism for sulfates stops, thus preventing formation of hydrogen sulfide.<ref name=BENTZEN>{{cite journal|title=Controlled dosing of nitrate for prevention of H<sub>2</sub>S in a sewer network and the effects on the subsequent treatment process|journal=Water Science and Technology|volume=31|issue=7|pages=293|doi=10.1016/0273-1223(95)00346-O|year=1995|last1=Bentzen|first1=G|last2=Smith|first2=A|last3=Bennett|first3=D|last4=Webster|first4=N|last5=Reinholt|first5=F|last6=Sletholt|first6=E|last7=Hobson|first7=J}}</ref> Additionally, easily degradable organic matter is consumed, which otherwise can cause anaerobic conditions downstream as well as odour emissions itself. The concept is also applicable for surplus sludge treatment.<ref name=EINARSEN>{{cite journal|author1=Einarsen, A.M.|author2= ÆeesØy, A.|author3= Rasmussen, A. I.|author4= Bungum, S.|author5= Sveberg, M. |year=2000|title= Biological prevention and removal of hydrogen sulphide in sludge at Lillehammer Wastewater Treatment Plant|journal= Water Sci. Technol. |volume=41|issue=6|pages=175–187|doi= 10.2166/wst.2000.0107}}</ref>
{{clr|left}}

===Concrete===
Calcium nitrate is used in concrete admixtures to accelerate setting.  This use with [[concrete]] and [[Mortar (masonry)|mortar]] is based on two effects. The calcium ion accelerates formation of calcium hydroxide and thus precipitation and setting. This effect is used also in cold weather concreting agents as well as some combined [[plasticizer]]s.<ref name=JUSTNES2010>Justines, H. (2010) "Calcium Nitrate as a Multifunctional Concrete Admixture" Concrete Magazine, Vol 44, No. 1, p.34. {{ISSN|0010-5317}}</ref> The nitrate ion leads to formation of iron hydroxide, whose protective layer reduces corrosion of the concrete reinforcement.<ref name=ALMOUDI>{{cite journal|doi=10.1016/S0958-9465(02)00084-7|title=Effectiveness of corrosion inhibitors in contaminated concrete|journal=Cement and Concrete Composites|volume=25|issue=4–5|pages=439|year=2003|last1=Al-Amoudi|first1=Omar S.Baghabra|last2=Maslehuddin|first2=Mohammed|last3=Lashari|first3=A.N|last4=Almusallam|first4=Abdullah A}}</ref>

===Latex coagulant ===
Calcium nitrate is a very common coagulant in latex production,  especially in dipping processes. Dissolved calcium nitrate is a part of the dipping bath solution. The warm former is dipped into the coagulation liquid and a thin film of the dipping liquid remains on the former. When now dipping the former into the latex the calcium nitrate will break up the stabilization of the latex solution and the latex will coagulate on the former.<ref name=DAFADER>N. C. Dafader, Y. N. Jolly, M. E. Haque, F. Akhtar & M. U. Ahmad:  The Role of Coagulants on the Preparation of Dipped film from Radiation Vulcanized Natural Rubber Latex. Polymer-Plastics Technology and Engineering. Volume 38, Issue 2, 1999, pages 267-274. Online: http://www.tandfonline.com/doi/abs/10.1080/03602559909351576</ref><ref name=RUBBERCARE>{{Cite web | url=http://www.rubbercare.com.my/process.html | title=Rubbercare - Choice Latex and Nitrile Gloves from a Trusted Manufacturer}}</ref>

===Cold packs===
The dissolution of calcium nitrate tetrahydrate is highly endothermic (cooling).  For this reason, calcium nitrate tetrahydrate is sometimes used for regenerable cold packs.<ref name=Ullmann/>

===Molten salts for heat transfer and storage ===
Calcium nitrate can be used as a part of molten salt mixtures. Typical are binary mixtures of calcium nitrate and [[potassium nitrate]] or ternary mixtures including also [[sodium nitrate]].<ref name=SolarNovus>{{Cite web | url=http://www.solarnovus.com/potassium-calcium-nitrate-promising-for-csp-heat-storage_N6044.html | title=Potassium calcium nitrate promising for CSP heat storage – Solar Novus Today}}</ref><ref name= EP0049761>European Patent Application EP0049761: Use of a ternary mixture of salts as a heat transmitting medium and/or as a heat storage medium. http://www.freepatentsonline.com/EP0049761A1.html</ref><ref name= WO-2014-044652>WIPO Patent Application WO/2014/044652: Use of a calcium potassium nitrate salt for the manufacture of a heat transfer fluid. http://www.freepatentsonline.com/WO2014044652A1.html</ref> Those molten salts can be used to replace thermo oil in concentrated solar power plants for the heat transfer, but mostly those are used in heat storage.

== References ==
{{Reflist}}

{{Calcium compounds}}
{{nitrates}}

[[Category:Calcium compounds]]
[[Category:Nitrates]]
[[Category:Nitrate minerals]]
[[Category:Pyrotechnic oxidizers]]
[[Category:Pyrotechnic colorants]]
[[Category:Inorganic fertilizers]]
[[Category:Concrete admixtures]]