Calcium nitrate

Structural formula
General
Surname	Calcium nitrate
other names	Wall nitrate; Calcium nitrate;
Molecular formula	Ca (NO 3 ) 2 (anhydrous); Ca (NO 3 ) 2 4 H 2 O (tetrahydrate);
Brief description	colorless, deliquescent, monoclinic prisms (tetrahydrate)
External identifiers / databases
EC number	233-332-1
ECHA InfoCard	100.030.289
PubChem	24963
ChemSpider	23336
Wikidata	Q407392
properties
Molar mass	164.09 g · mol -1 (anhydrous); 236.15 g · mol -1 (tetrahydrate);
Physical state	firmly
density	2.466 g cm −3 (anhydrous); 1.82 g cm −3 (tetrahydrate);
Melting point	561 ° C (anhydrous); 45 ° C (tetrahydrate);
solubility	good in water (1470 g l −1 at 0 ° C, 2710 g l −1 at 40 ° C as tetrahydrate)
safety instructions
H and P phrases	H: 272-302-318
	P: 280-305 + 351 + 338
Toxicological data	302 mg kg −1 ( LD 50 , rat , oral , anhydrous) ; 3900 mg kg −1 ( LD 50 , rat , oral , tetrahydrate) ;
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Calcium nitrate is the calcium salt of nitric acid and has the molecular formula Ca (NO ₃ ) ₂ . "Lime or normal nitrate" is used as a fertilizer . The name "Norgesalpeter" comes from the Norwegians Kristian Birkeland and Sam Eyde , who developed a process for producing saltpetre.

Occurrence

Calcium nitrate is formed when ammonium nitrate from animal manure or urine penetrates walls with the help of moisture transported by capillary action and reacts with the lime from the cement mortar or the lime mortar that was once more commonly used . This is how the so-called wall salt or wall nitrate is created , which slowly destroys the walls (for example of cattle sheds, cellars and toilets). In history there have been saltpetre workers who wandered around scratching, cleaning and selling this blooming salt from the walls. Due to its high water attraction, it cannot be used directly, but must be converted to potassium nitrate with the help of potash . Black powder has been made from this product since the Middle Ages .

Because of its fluorescent properties, it was also known as Balduin's phosphorus in the 17th century after the discoverer, Christian Adolf Balduin .

The tetrahydrate of calcium nitrate occurs naturally in the form of the mineral nitrocalcite .

Wall salts with a different composition are also formed when free sulfuric acid from the condensate of heating gases acts on the cement and the carbonate-containing additives in mortar , chimney stones and plaster. Among other things, the lime contained in the cement is converted into gypsum and ettringite . The reaction products "float", that is, they swell , and shatter the building material . Such wet wall structure can also be impaired in winter by frost bursts.

Extraction and presentation

Calcium nitrate can be prepared from calcium carbonate or calcium oxide and nitric acid :

{\ displaystyle \ mathrm {CaCO_ {3} +2 \ HNO_ {3} \ longrightarrow \ Ca (NO_ {3}) _ {2} + CO_ {2} + H_ {2} O}}

{\ displaystyle \ mathrm {CaO + 2 \ HNO_ {3} \ longrightarrow \ Ca (NO_ {3}) _ {2} + H_ {2} O}}

The reaction of calcium with nitric acid is also possible:

{\ displaystyle \ mathrm {Ca + 2 \ HNO_ {3} \ longrightarrow \ Ca (NO_ {3}) _ {2} + H_ {2}}}

Calcium nitrate also forms a kind of white veil on walls that has the consistency of cotton wool. You can sweep it off with a broom or remove it with a spatula . The salt is dissolved in water, the impurities then sink to the bottom. The salt solution is poured off, carefully evaporated and dried. However, it is mostly contaminated with other salts.

See: Saltpeter

properties

Calcium nitrate is a white, hygroscopic, oxidizing solid that is very easily soluble in water. It forms a number of hydrates, such as a di-, tri- and tetrahydrate. The compound decomposes when heated, producing oxygen and nitrogen oxides . The tetrahydrate begins to split off water of crystallization at temperatures above 100 ° C, above 130 ° C, oxygen splits off and from 225 ° C onwards, decomposition to calcium oxide begins . As a tetrahydrate it forms colorless, deliquescent, monoclinic prisms.

The tetrahydrate has a monoclinic crystal structure with the space group P 2 ₁ / n (space group no. 14, position 2) and is dimeric. The anhydrate has a cubic crystal structure with the space group Pa 3 (space group no. 205) . Template: room group / 14.2 Template: room group / 205

use

In addition to its use as a fertilizer, calcium nitrate is also recommended as a component in cooling brines and in latex coagulation baths. It is also used as a starting material for the production of other calcium compounds or calcium-containing materials, e.g. B. calcium phosphate , calcium silicate nanocrystals, hydroxyapatite fibers and electrically conductive ceramic materials. It is also used in the manufacture of pyrotechnic articles ( explosives ), bone implants and in the electronics industry for radio tubes. Another application is the addition in sewers in order to prevent the formation of H ₂ S. In the building industry , calcium nitrate is used as the main ingredient in setting accelerators for concrete .

Individual evidence

↑ ^a ^b ^c Entry on calcium nitrate. In: Römpp Online . Georg Thieme Verlag, accessed on July 15, 2014.
↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ Entry on calcium nitrate in the GESTIS substance database of the IFA , accessed on January 10, 2017 (JavaScript required)
↑ ^a ^b Data sheet Calcium nitrate tetrahydrate from Sigma-Aldrich , accessed on February 1, 2017 ( PDF ).
↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Inorganic Compounds, pp. 4-55.
^ Wilhelm Hassenstein: The fireworks book from 1420. 600 years of German powder weapons and gunsmithing. Reprint of the first edition from 1529 (published in the same year by Egenolph in Strasbourg under the title Büchsenmeysterei ) with translation into standard German and explanations, Munich 1941, pp. 49 and 53.
↑ C. Doelter: The elements and compounds of: Ti, Zr, Sn, Th, Nb, Ta, N, P, As, Sb, Bi, V and H Volume III. First department . Springer-Verlag, 2013, ISBN 978-3-642-49781-0 , p. 290 ( limited preview in Google Book Search).
↑ B. RIBAR, V. Divjaković: A new crystal structure study of Ca (NO ₃ ) ₂ · 4 H ₂ O . In: Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry . tape 29 , no. 7 , July 15, 1973, ISSN 0567-7408 , p. 1546-1548 , doi : 10.1107 / S0567740873004929 .
↑ Angel Vegas: Inorganic 3D Structures . Springer, 2011, ISBN 978-3-642-20341-1 , pp. 48 ( limited preview in Google Book search).
^ Josef Köhler, Rudolf Meyer, Axel Homburg: Explosivstoffe . Tenth, completely revised edition. John Wiley & Sons, 2012, ISBN 3-527-66007-0 ( limited preview in Google Book Search).
↑ http://www.schwefelwasserstoff.de/Ca(NO3)2.html
↑ Sika: Safety data sheet Sika Rapid C-100. Retrieved November 6, 2017 .

[roempp-1] Entry on calcium nitrate. In: Römpp Online . Georg Thieme Verlag, accessed on July 15, 2014.

[GESTIS-2] ↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ Entry on calcium nitrate in the GESTIS substance database of the IFA , accessed on January 10, 2017 (JavaScript required)

[SIGMA-3] Data sheet Calcium nitrate tetrahydrate from Sigma-Aldrich , accessed on February 1, 2017 ( PDF ).

[CRC90-4] David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Inorganic Compounds, pp. 4-55.

[5] Wilhelm Hassenstein: The fireworks book from 1420. 600 years of German powder weapons and gunsmithing. Reprint of the first edition from 1529 (published in the same year by Egenolph in Strasbourg under the title Büchsenmeysterei ) with translation into standard German and explanations, Munich 1941, pp. 49 and 53.

[C._Doelter-6] C. Doelter: The elements and compounds of: Ti, Zr, Sn, Th, Nb, Ta, N, P, As, Sb, Bi, V and H Volume III. First department . Springer-Verlag, 2013, ISBN 978-3-642-49781-0 , p. 290 ( limited preview in Google Book Search).

[7] B. RIBAR, V. Divjaković: A new crystal structure study of Ca (NO ₃ ) ₂ · 4 H ₂ O . In: Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry . tape 29 , no. 7 , July 15, 1973, ISSN 0567-7408 , p. 1546-1548 , doi : 10.1107 / S0567740873004929 .

[Angel_Vegas-8] Angel Vegas: Inorganic 3D Structures . Springer, 2011, ISBN 978-3-642-20341-1 , pp. 48 ( limited preview in Google Book search).

[9] Josef Köhler, Rudolf Meyer, Axel Homburg: Explosivstoffe . Tenth, completely revised edition. John Wiley & Sons, 2012, ISBN 3-527-66007-0 ( limited preview in Google Book Search).

[10] ttp://www.schwefelwasserstoff.de/Ca(NO3)2.html

[11] Sika: Safety data sheet Sika Rapid C-100. Retrieved November 6, 2017 .