Strontium chloride

Chemical compound From Wikipedia, the free encyclopedia

Strontium chloride

Strontium chloride (SrCl2) is a salt of strontium and chloride. 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.[citation needed] Its properties are intermediate between those for barium chloride, which is more toxic, and calcium chloride.

Quick Facts Names, Identifiers ...
Strontium chloride
Thumb
Strontium chloride hexahydrate
Names
IUPAC name
Strontium chloride
Other names
Strontium(II) chloride
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.030.870
EC Number
  • 233-971-6
UNII
  • InChI=1S/2ClH.Sr/h2*1H;/q;;+2/p-2 Y
    Key: AHBGXTDRMVNFER-UHFFFAOYSA-L Y
  • 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)
Appearance White 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)
ThumbHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
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).
N verify (what is YN ?)
Close

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

In the solid state, SrCl2 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

Summarize
Perspective

Strontium chloride is a precursor to other compounds of strontium, such as yellow strontium chromate, strontium carbonate, and strontium sulfate. Exposure of aqueous solutions of strontium chloride to the sodium salt of the desired anion often leads to formation of the solid precipitate:[9][2]

SrCl2 + Na2CrO4 → SrCrO4 + 2 NaCl
SrCl2 + Na2CO3 → SrCO3 + 2 NaCl
SrCl2 + Na2SO4 → SrSO4 + 2 NaCl

Strontium chloride is often used as a red colouring agent in pyrotechnics.[citation needed] It imparts a much more intense red colour to the flames than most 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.

Ammonia storage

A commercial company is using a strontium chloride-based artificial solid called AdAmmine as a means to store ammonia 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 ammonia as a means to store synthetic ammonia 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 a universal extractant of plant nutrients.[14]

References

Loading related searches...

Wikiwand - on

Seamless Wikipedia browsing. On steroids.