Sodium bromide

From Wikipedia, the free encyclopedia - View original article

Sodium bromide
3D model of sodium bromide
Sodium bromide powder
Identifiers
CAS number7647-15-6 YesY, 13466-08-5 (dihydrate) YesY
PubChem253881
ChemSpider22712 YesY
UNIILC1V549NOM YesY
ChEMBLCHEMBL1644694 N
RTECS numberVZ3150000
Jmol-3D imagesImage 1
Properties
Molecular formulaBrNa
Molar mass102.89 g mol−1
AppearanceWhite powder, hygroscopic
Density3.21 g/cm3 (anhydrous)
2.18 g/cm3 (dihydrate)
Melting point747 °C (1,377 °F; 1,020 K)
(anhydrous)
36 °C (97 °F; 309 K)
(dihydrate) decomposes[3]
Boiling point1,390 °C (2,530 °F; 1,660 K) [3]
Solubility in water71.35 g/100 mL (−20 °C)
79.52 g/100 mL (0 °C)
94.32 g/100 mL (25 °C)[1]
104.9 g/100 mL (40 °C)
116.2 g/100 mL (100 °C)[2]
SolubilitySoluble in alcohol, liquid ammonia, acetone, pyridine, hydrazine, acetonitrile, SO2, amine[1]
Solubility in methanol17.3 g/100 g (0 °C)
16.8 g/100 g (20 °C)
16.1 g/100 g (40 °C)
15.3 g/100 g (60 °C)[1]
Solubility in ethanol2.45 g/100 g (0 °C)
2.32 g/100 g (20 °C)
2.29 g/100 g (30 °C)
2.35 g/100 g (70 °C)[1]
Solubility in formic acid19.3 g/100 g (18 °C)
19.4 g/100 g (25 °C)[1]
Solubility in glycerol38.7 g/100 g (20 °C)[1]
Solubility in dimethylformamide3.2 g/100 g (10.3 °C)[1]
Vapor pressure1 torr (806 °C)
5 torr (903 °C)[3]
Thermal conductivity5.6 W/m·K (150 K)[4]
Refractive index (nD)1.6428 (24 °C)
nKrF = 1.8467 (24 °C)
nHe–Ne = 1.6389 (24 °C)[5]
Viscosity1.42 cP (762 °C)
1.08 cP (857 °C)
0.96 cP (937 °C)[1]
Structure
Crystal structureCubic
Lattice constanta = 5.97 Å[4]
Thermochemistry
Specific
heat capacity
C
51.4 J/mol·K[1]
Std molar
entropy
So298
86.82 J/mol·K[1]
Std enthalpy of
formation
ΔfHo298
−361.41 kJ/mol[1]
Gibbs free energy ΔG−349.3 kJ/mol[1]
Hazards
MSDSExternal MSDS
EU IndexNot listed
R-phrasesR36
S-phrases(S2), S24/25, S46
NFPA 704
Flash point800 °C (1,470 °F; 1,070 K)
LD503500 mg/kg (rats, oral)
Related compounds
Other anionsSodium fluoride
Sodium chloride
Sodium iodide
Other cationsLithium bromide
Potassium bromide
Rubidium bromide
Caesium bromide
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 N (verify) (what is: YesY/N?)
Infobox references
 
Jump to: navigation, search
Sodium bromide
3D model of sodium bromide
Sodium bromide powder
Identifiers
CAS number7647-15-6 YesY, 13466-08-5 (dihydrate) YesY
PubChem253881
ChemSpider22712 YesY
UNIILC1V549NOM YesY
ChEMBLCHEMBL1644694 N
RTECS numberVZ3150000
Jmol-3D imagesImage 1
Properties
Molecular formulaBrNa
Molar mass102.89 g mol−1
AppearanceWhite powder, hygroscopic
Density3.21 g/cm3 (anhydrous)
2.18 g/cm3 (dihydrate)
Melting point747 °C (1,377 °F; 1,020 K)
(anhydrous)
36 °C (97 °F; 309 K)
(dihydrate) decomposes[3]
Boiling point1,390 °C (2,530 °F; 1,660 K) [3]
Solubility in water71.35 g/100 mL (−20 °C)
79.52 g/100 mL (0 °C)
94.32 g/100 mL (25 °C)[1]
104.9 g/100 mL (40 °C)
116.2 g/100 mL (100 °C)[2]
SolubilitySoluble in alcohol, liquid ammonia, acetone, pyridine, hydrazine, acetonitrile, SO2, amine[1]
Solubility in methanol17.3 g/100 g (0 °C)
16.8 g/100 g (20 °C)
16.1 g/100 g (40 °C)
15.3 g/100 g (60 °C)[1]
Solubility in ethanol2.45 g/100 g (0 °C)
2.32 g/100 g (20 °C)
2.29 g/100 g (30 °C)
2.35 g/100 g (70 °C)[1]
Solubility in formic acid19.3 g/100 g (18 °C)
19.4 g/100 g (25 °C)[1]
Solubility in glycerol38.7 g/100 g (20 °C)[1]
Solubility in dimethylformamide3.2 g/100 g (10.3 °C)[1]
Vapor pressure1 torr (806 °C)
5 torr (903 °C)[3]
Thermal conductivity5.6 W/m·K (150 K)[4]
Refractive index (nD)1.6428 (24 °C)
nKrF = 1.8467 (24 °C)
nHe–Ne = 1.6389 (24 °C)[5]
Viscosity1.42 cP (762 °C)
1.08 cP (857 °C)
0.96 cP (937 °C)[1]
Structure
Crystal structureCubic
Lattice constanta = 5.97 Å[4]
Thermochemistry
Specific
heat capacity
C
51.4 J/mol·K[1]
Std molar
entropy
So298
86.82 J/mol·K[1]
Std enthalpy of
formation
ΔfHo298
−361.41 kJ/mol[1]
Gibbs free energy ΔG−349.3 kJ/mol[1]
Hazards
MSDSExternal MSDS
EU IndexNot listed
R-phrasesR36
S-phrases(S2), S24/25, S46
NFPA 704
Flash point800 °C (1,470 °F; 1,070 K)
LD503500 mg/kg (rats, oral)
Related compounds
Other anionsSodium fluoride
Sodium chloride
Sodium iodide
Other cationsLithium bromide
Potassium bromide
Rubidium bromide
Caesium bromide
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 N (verify) (what is: YesY/N?)
Infobox references

Sodium bromide is an inorganic compound with the formula NaBr. It is a high-melting white, crystalline solid that resembles sodium chloride. It is a widely used source of the bromide ion and has many applications.[7]

Synthesis, structure, reactions[edit]

NaBr crystallizes in the same cubic motif as NaCl, NaF and NaI. The anhydrous salt crystallizes above 50.7 °C.[7] Dihydrate salts (NaBr·2H2O) begins to anhydrous at 50.7 °C in water solution.[2]

It is produced by treating sodium hydroxide with hydrogen bromide.

Sodium bromide can be used as a source of the chemical element bromine. This can be accomplished by treating an aqueous solution of NaBr with chlorine gas:

2 NaBr + Cl2 → Br2 + 2 NaCl

Applications[edit]

Sodium bromide is the most useful inorganic bromide in industry.[7]

Medicine[edit]

Also known as Sedoneural, sodium bromide has been used as a hypnotic, anticonvulsant, and sedative in medicine, widely used as an anticonvulsant and a sedative in the late 19th and early 20th centuries. Its action is due to the bromide ion, and for this reason potassium bromide is equally effective. In 1975, bromides were removed from drugs in the U.S. such as Bromo-Seltzer due to toxicity.[8]

Preparation of other bromine compounds[edit]

Sodium bromide is widely used for the preparation of other bromides in organic synthesis and other areas. It is a source of the bromide nucleophile to convert alkyl chlorides to more reactive alkyl bromides by the Finkelstein reaction:

NaBr + RCl → RBr + NaCl (R = alkyl)

Once a large need in photography, but now shrinking, the photosensitive salt silver bromide is prepared using NaBr.

Disinfectant[edit]

Sodium bromide is used in conjunction with chlorine as a disinfectant for swimming pools.

Petroleum industry[edit]

Sodium bromide is used to prepare dense fluids used in oil wells.

Safety[edit]

NaBr has a very low toxicity with an oral LD50 estimated at 3.5 g/kg for rats.[6] However, this is a single-dose value. Bromide ion is a cumulative toxin with a relatively long half life (in excess of a week in humans): see potassium bromide.

References[edit]

  1. ^ a b c d e f g h i j k l http://chemister.ru/Database/properties-en.php?dbid=1&id=714
  2. ^ a b Seidell, Atherton; Linke, William F. (1919). Solubilities of Inorganic and Organic Compounds (2nd ed.). D. Van Nostrand Company. 
  3. ^ a b c Pradyot, Patnaik (2003). Handbook of Inorganic Chemicals. The McGraw-Hill Companies, Inc. ISBN 0-07-049439-8. 
  4. ^ a b "Sodium Bromide (NaBr)". http://www.korth.de. Korth Kristalle GmbH. Retrieved 2014-06-11. 
  5. ^ Polyanskiy, Mikhail. "Refractive index of NaBr (Sodium bromide) - Li". http://www.refractiveindex.info. Retrieved 2014-06-11. 
  6. ^ a b "Sodium bromide MSDS" (PDF). http://www.sciencelab.com. Sciencelab.com, Inc. 2013-05-21. Retrieved 2014-06-11. 
  7. ^ a b c Michael J. Dagani, Henry J. Barda, Theodore J. Benya, David C. Sanders "Bromine Compounds" in Ullmann's Encyclopedia of Industrial Chemistry Wiley-VCH, Weinheim, 2000. doi:10.1002/14356007.a04_405
  8. ^ "Bromide: Potassium & Sodium". http://www.canine-epilepsy.com. Canine-Epilepsy Resources. 2011-05-31. Retrieved 2014-06-11. 

External links[edit]