Strontium chloride

Last updated
Strontium chloride
Strontium chloride hexahydrate.jpg
Names
IUPAC name
Strontium chloride
Other names
Strontium(II) chloride
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.030.870 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 233-971-6
PubChem CID
UNII
  • InChI=1S/2ClH.Sr/h2*1H;/q;;+2/p-2 Yes check.svgY
    Key: AHBGXTDRMVNFER-UHFFFAOYSA-L Yes check.svgY
  • InChI=1S/2ClH.Sr/h2*1H;/q;;+2/p-2
  • Key: AHBGXTDRMVNFER-UHFFFAOYSA-L
  • [Sr+2].[Cl-].[Cl-]
Properties
SrCl2
Molar mass 158.53 g/mol (anhydrous)
266.62 g/mol (hexahydrate)
AppearanceWhite crystalline solid
Density 3.052 g/cm3 (anhydrous, monoclinic form)
2.672 g/cm3 (dihydrate)
1.930 g/cm3 (hexahydrate)
Melting point 874 °C (1,605 °F; 1,147 K) (anhydrous)
61 °C (hexahydrate)
Boiling point 1,250 °C (2,280 °F; 1,520 K) (anhydrous)
anhydrous:
53.8 g/100 mL (20 °C)
hexahydrate:
106 g/100 mL (0 °C)
206 g/100 mL (40 °C)
Solubility ethanol: very slightly soluble
acetone: very slightly soluble
ammonia: insoluble
63.0·10−6 cm3/mol
1.650 (anhydrous)
1.594 (dihydrate)
1.536 (hexahydrate) [1]
Structure
Deformed rutile structure
octahedral (six-coordinate)
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
Irritant
NFPA 704 (fire diamond)
2
0
0
Flash point N/A
Related compounds
Other anions
Strontium fluoride
Strontium bromide
Strontium iodide
Other cations
Beryllium chloride
Magnesium chloride
Calcium chloride
Barium chloride
Radium chloride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
X mark.svgN  verify  (what is  Yes check.svgYX mark.svgN ?)

Strontium chloride (SrCl2) is a salt of strontium and chlorine.

Contents

It is a 'typical' salt, forming neutral aqueous solutions. As with all compounds of strontium, this salt emits a bright red colour in flame, and is commonly used in fireworks to that effect.

Its chemical properties are intermediate between those for barium chloride, which is more toxic, and calcium chloride.

Preparation

Strontium chloride can be prepared by treating aqueous strontium hydroxide or strontium carbonate with hydrochloric acid:

Sr(OH)2 + 2 HCl → SrCl2 + 2 H2O

Crystallization from cold aqueous solution gives the hexahydrate, SrCl2·6H2O. Dehydration of this salt occurs in stages, commencing above 61 °C (142 °F). Full dehydration occurs at 320 °C (608 °F). [2]

Structure

The crystalline solid adopts a fluorite structure. [3] [4] [5] In the vapour phase the SrCl2 molecule is non-linear with a Cl-Sr-Cl angle of approximately 130°. [6] This is an exception to VSEPR theory which would predict a linear structure. Ab initio calculations have been cited to propose that contributions from d orbitals in the shell below the valence shell are responsible. [7] Another proposal is that polarisation of the electron core of the strontium atom causes a distortion of the core electron density that interacts with the Sr-Cl bonds. [8]

Uses

Strontium chloride is a precursor to other compounds of strontium, such as yellow strontium chromate, strontium carbonate, and strontium sulfate. Exposure of strontium chloride to the sodium salt of the desired anion (or alternately carbon dioxide gas to form the carbonate) leads to precipitation of the salt: [9] [2]

SrCl2 + Na2CrO4 → SrCrO4 + 2 NaCl
SrCl2 + Na2CO3 → SrCO3 + 2 NaCl
SrCl2 + H2O + CO2 → SrCO3 + 2 HCl
SrCl2 + Na2SO4 → SrSO4 + 2 NaCl

Strontium chloride is often used as a red colouring agent in pyrotechnics. It imparts a much more intense red colour to the flames than most other alternatives. It is employed in small quantities in glass-making and metallurgy. The radioactive isotope strontium-89, used for the treatment of bone cancer, is usually administered in the form of strontium chloride. Seawater aquaria require small amounts of strontium chloride, which is consumed during the growth of certain plankton.

Dental care

SrCl2 is useful in reducing tooth sensitivity by forming a barrier over microscopic tubules in the dentin containing nerve endings that have become exposed by gum recession. Known in the U.S. as Elecol and Sensodyne, these products are called "strontium chloride toothpastes", although most now use saltpeter (KNO3) instead which works as an analgesic rather than a barrier. [10]

Biological research

Brief strontium chloride exposure induces parthenogenetic activation of oocytes [11] which is used in developmental biological research.

Ammonium storage

A commercial company is using a strontium chloride-based artificial solid called AdAmmine as a means to store ammonium at low pressure, mainly for use in NOx emission reduction on Diesel vehicles. They claim that their patented material can also be made from some other salts, but they have chosen strontium chloride for mass production. [12] Earlier company research also considered using the stored ammonium as a means to store synthetic Ammonium fuel under the trademark HydrAmmine and the press name "hydrogen tablet", however, this aspect has not been commercialized. [13] Their processes and materials are patented. Their early experiments used magnesium chloride, and is also mentioned in that article.

Soil testing

Strontium chloride is used with citric acid in soil testing as an universal extractant of plant nutrients. [14]

Related Research Articles

<span class="mw-page-title-main">Acid</span> Chemical compound giving a proton or accepting an electron pair

An acid is a molecule or ion capable of either donating a proton (i.e. hydrogen ion, H+), known as a Brønsted–Lowry acid, or forming a covalent bond with an electron pair, known as a Lewis acid.

<span class="mw-page-title-main">Acid–base reaction</span> Chemical reaction

An acid–base reaction is a chemical reaction that occurs between an acid and a base. It can be used to determine pH via titration. Several theoretical frameworks provide alternative conceptions of the reaction mechanisms and their application in solving related problems; these are called the acid–base theories, for example, Brønsted–Lowry acid–base theory.

In chemistry, a salt is a chemical compound consisting of an ionic assembly of positively charged cations and negatively charged anions, which results in a compound with no net electric charge. A common example is table salt, with positively charged sodium ions and negatively charged chloride ions.

<span class="mw-page-title-main">Perchloric acid</span> Chemical compound

Perchloric acid is a mineral acid with the formula HClO4. Usually found as an aqueous solution, this colorless compound is a stronger acid than sulfuric acid, nitric acid and hydrochloric acid. It is a powerful oxidizer when hot, but aqueous solutions up to approximately 70% by weight at room temperature are generally safe, only showing strong acid features and no oxidizing properties. Perchloric acid is useful for preparing perchlorate salts, especially ammonium perchlorate, an important rocket fuel component. Perchloric acid is dangerously corrosive and readily forms potentially explosive mixtures.

<span class="mw-page-title-main">Sodium carbonate</span> Chemical compound

Sodium carbonate, Na2CO3, (also known as washing soda, soda ash and soda crystals) is the inorganic compound with the formula Na2CO3 and its various hydrates. All forms are white, odourless, water-soluble salts that yield moderately alkaline solutions in water. Historically, it was extracted from the ashes of plants growing in sodium-rich soils. Because the ashes of these sodium-rich plants were noticeably different from ashes of wood (once used to produce potash), sodium carbonate became known as "soda ash". It is produced in large quantities from sodium chloride and limestone by the Solvay process.

The compound hydrogen chloride has the chemical formula HCl and as such is a hydrogen halide. At room temperature, it is a colourless gas, which forms white fumes of hydrochloric acid upon contact with atmospheric water vapor. Hydrogen chloride gas and hydrochloric acid are important in technology and industry. Hydrochloric acid, the aqueous solution of hydrogen chloride, is also commonly given the formula HCl.

<span class="mw-page-title-main">Zinc chloride</span> Chemical compound

Zinc chloride is the name of inorganic chemical compounds with the formula ZnCl2 and its hydrates. Zinc chlorides, of which nine crystalline forms are known, are colorless or white, and are highly soluble in water. This salt is hygroscopic and even deliquescent. Zinc chloride finds wide application in textile processing, metallurgical fluxes, and chemical synthesis. No mineral with this chemical composition is known aside from the very rare mineral simonkolleite, Zn5(OH)8Cl2·H2O.

<span class="mw-page-title-main">Praseodymium(III) chloride</span> Chemical compound

Praseodymium(III) chloride is the inorganic compound with the formula PrCl3. Like other lanthanide trichlorides, it exists both in the anhydrous and hydrated forms. It is a blue-green solid that rapidly absorbs water on exposure to moist air to form a light green heptahydrate.

Neodymium(III) chloride or neodymium trichloride is a chemical compound of neodymium and chlorine with the formula NdCl3. This anhydrous compound is a mauve-colored solid that rapidly absorbs water on exposure to air to form a purple-colored hexahydrate, NdCl3·6H2O. Neodymium(III) chloride is produced from minerals monazite and bastnäsite using a complex multistage extraction process. The chloride has several important applications as an intermediate chemical for production of neodymium metal and neodymium-based lasers and optical fibers. Other applications include a catalyst in organic synthesis and in decomposition of waste water contamination, corrosion protection of aluminium and its alloys, and fluorescent labeling of organic molecules (DNA).

Classical qualitative inorganic analysis is a method of analytical chemistry which seeks to find the elemental composition of inorganic compounds. It is mainly focused on detecting ions in an aqueous solution, therefore materials in other forms may need to be brought to this state before using standard methods. The solution is then treated with various reagents to test for reactions characteristic of certain ions, which may cause color change, precipitation and other visible changes.

<span class="mw-page-title-main">Samarium(III) chloride</span> Chemical compound

Samarium(III) chloride, also known as samarium trichloride, is an inorganic compound of samarium and chloride. It is a pale yellow salt that rapidly absorbs water to form a hexahydrate, SmCl3.6H2O. The compound has few practical applications but is used in laboratories for research on new compounds of samarium.

<span class="mw-page-title-main">Copper(II) chloride</span> Chemical compound

Copper(II) chloride is the chemical compound with the chemical formula CuCl2. The anhydrous form is yellowish brown but slowly absorbs moisture to form a blue-green dihydrate.

<span class="mw-page-title-main">Hexafluorosilicic acid</span> Octahedric silicon compound

Hexafluorosilicic acid is an inorganic compound with the chemical formula H
2
SiF
6
. Aqueous solutions of hexafluorosilicic acid consist of salts of the cation and hexafluorosilicate anion. These salts and their aqueous solutions are colorless.

<span class="mw-page-title-main">Strontium carbonate</span> Chemical compound

Strontium carbonate (SrCO3) is the carbonate salt of strontium that has the appearance of a white or grey powder. It occurs in nature as the mineral strontianite.

<span class="mw-page-title-main">Strontium sulfate</span> Chemical compound

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).

Calcium chlorate is the calcium salt of chloric acid, with the chemical formula Ca(ClO3)2. Like other chlorates, it is a strong oxidizer.

<span class="mw-page-title-main">Monosodium phosphate</span> Chemical compound

Monosodium phosphate (MSP), also known as monobasic sodium phosphate and sodium dihydrogen phosphate, is an inorganic compound of sodium with a dihydrogen phosphate (H2PO4) anion. One of many sodium phosphates, it is a common industrial chemical. The salt exists in an anhydrous form, as well as mono- and dihydrates.

<span class="mw-page-title-main">Strontium sulfide</span> Chemical compound

Strontium sulfide is the inorganic compound with the formula SrS. It is a white solid. The compound is an intermediate in the conversion of strontium sulfate, the main strontium ore called celestite, to other more useful compounds.

<span class="mw-page-title-main">Hydrochloric acid</span> Strong mineral acid

Hydrochloric acid, also known as muriatic acid, is an aqueous solution of hydrogen chloride. It is a colorless solution with a distinctive pungent smell. It is classified as a strong acid. It is a component of the gastric acid in the digestive systems of most animal species, including humans. Hydrochloric acid is an important laboratory reagent and industrial chemical.

References

  1. Pradyot Patnaik. Handbook of Inorganic Chemicals. McGraw-Hill, 2002, ISBN   0-07-049439-8
  2. 1 2 J. Paul MacMillan, Jai Won Park, Rolf Gerstenberg, Heinz Wagner, Karl Köhler, Peter Wallbrecht "Strontium and Strontium Compounds" in Ullmann's Encyclopedia of Industrial Chemistry, 2005, Wiley-VCH: Weinheim. DOI 10.1002/14356007.a25 321
  3. West, Anthony R. (8 January 2014). Solid state chemistry and its applications (Second edition, student ed.). Chichester, West Sussex, UK. ISBN   978-1-118-67625-7. OCLC   854761803.
  4. Persson, Kristin (2020), Materials Data on SrCl2 by Materials Project, Materials Project, LBNL Materials Project; Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States), doi:10.17188/1199327 , retrieved 2020-10-10
  5. Mark, H.; Tolksdorf, S. (1925). "Ueber das Beugungsvermoegen der Atome fuer Roentgenstrahlen". www.crystallography.net. Retrieved 2020-10-10.
  6. Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN   978-0-08-037941-8.
  7. Ab initio model potential study of the equilibrium geometry of alkaline earth dihalides: MX2 (M=Mg, Ca Sr, Ba; X=F, Cl, Br, I) Seijo L., Barandiarán Z J. Chem. Phys. 94, 3762 (1991) doi : 10.1063/1.459748
  8. "Ion model and equilibrium configuration of the gaseous alkaline-earth dihalides" Guido M. and Gigli G. J. Chem. Phys. 65, 1397 (1976); doi : 10.1063/1.433247
  9. Aydoğan, Salih; Erdemoğlu, Murat; Aras, Ali; Uçar, Gökhan; Özkan, Alper (2006). "Dissolution kinetics of celestite (SrSO4) in HCl solution with BaCl2". Hydrometallurgy. 84 (3–4): 239–246. doi:10.1016/j.hydromet.2006.06.001.
  10. "Sensodyne". Sensodyne. Archived from the original on 2008-09-18. Retrieved 2008-09-05.
  11. O'Neill GT, Rolfe LR, Kaufman MH. "Developmental potential and chromosome constitution of strontium-induced mouse parthenogenones" (1991) Mol. Reprod. Dev. 30:214-219
  12. "AdAmmine™". Amminex A/S. Archived from the original on 2013-08-01. Retrieved 2013-06-12.
  13. Tue Johannesen (May 2012). 'Solidified' ammonia as an energy storage material for fuel cell applications (PDF). 2006 Annual NH3 Fuel Conference, October 9 – 10, 2006, Golden, CO. Amminex. Retrieved 2022-11-16. Via NH3 Fuel Association website.
  14. Simard, R. R. (1 March 1991). "Strontium Chloride-Citric Acid Extraction Evaluated as a Soil-Testing Procedure for Phosphorus". Soil Science Society of America Journal. doi:10.2136/sssaj1991.03615995005500020021x.