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| IUPAC name Sodium bromide | |
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| ECHA InfoCard | 100.028.727 |
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| Properties | |
| NaBr | |
| Molar mass | 102.894 g·mol−1 |
| Appearance | White powder,hygroscopic |
| Density | 3.21 g/cm3 (anhydrous) 2.18 g/cm3 (dihydrate) |
| Melting point | 747 °C (1,377 °F; 1,020 K) (anhydrous) 36 °C (97 °F; 309 K) (dihydrate) decomposes[3] |
| Boiling point | 1,390 °C (2,530 °F; 1,660 K)[3] |
| 71.35 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] | |
| Solubility | Soluble inalcohol, liquidammonia,pyridine,hydrazine,SO2 Insoluble inacetone,acetonitrile[1] |
| Solubility inmethanol | 17.3 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 inethanol | 2.45 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 informic acid | 19.3 g/100 g (18 °C) 19.4 g/100 g (25 °C)[1] |
| Solubility inglycerol | 38.7 g/100 g (20 °C)[1] |
| Solubility indimethylformamide | 3.2 g/100 g (10.3 °C)[1] |
| Vapor pressure | 1 torr (806 °C) 5 torr (903 °C)[3] |
| −41.0·10−6 cm3/mol | |
| Thermal conductivity | 5.6 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] |
| Viscosity | 1.42 cP (762 °C) 1.08 cP (857 °C) 0.96 cP (937 °C)[1] |
| Structure | |
| Cubic | |
a = 5.97 Å[4] | |
| Thermochemistry | |
| 51.4 J/(mol·K)[1] | |
Std molar entropy(S⦵298) | 86.82 J/(mol·K)[1] |
Std enthalpy of formation(ΔfH⦵298) | −361.41 kJ/mol[1] |
Gibbs free energy(ΔfG⦵) | −349.3 kJ/mol[1] |
| Pharmacology | |
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| Hazards | |
| NFPA 704 (fire diamond) | |
| Flash point | 800 °C (1,470 °F; 1,070 K) |
| Lethal dose or concentration (LD, LC): | |
LD50 (median dose) | 3500 mg/kg (rats, oral) |
| Safety data sheet (SDS) | External MSDS |
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Otheranions | |
Othercations | |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Sodium bromide is aninorganic compound with the formulaNaBr. It is a high-melting white, crystalline solid that resemblessodium chloride. It is a widely used source of thebromide ion and has many applications.[7]
In repeated doses it is toxic to humans, leading tobromism, which may include symptoms such as skin rashes, drowsiness, nausea, and hallucinations.[8]
NaBr crystallizes in the samecubic motif asNaCl,NaF andNaI. Theanhydrous salt crystallizes above 50.7 °C.[7]Dihydrate salt (NaBr·2H2O) crystallize out of water solution below 50.7 °C.[9]
NaBr is produced by treatingsodium hydroxide withhydrogen bromide.
Sodium bromide can be used as a source of thechemical elementbromine. This can be accomplished by treating anaqueous solution of NaBr withchlorine gas:
Sodium bromide is the most useful inorganic bromide in industry.[7] It is also used as a catalyst in TEMPO-mediated oxidation reactions.[10]
Also known as Sedoneural,[11] sodium bromide has been used as ahypnotic,anticonvulsant, andsedative inmedicine, widely used as ananticonvulsant and asedative in the late 19th and early 20th centuries. Its action is due to the bromide ion, and for this reasonpotassium bromide is equally effective. In 1975, bromides were removed from drugs in the U.S. such asBromo-Seltzer due to toxicity.[12]
Sodium bromide is widely used for the preparation of other bromides inorganic synthesis and other areas. It is a source of the bromidenucleophile to convert alkyl chlorides to more reactive alkyl bromides by theFinkelstein reaction:
Once a large need inphotography, but now shrinking, the photosensitive saltsilver bromide is prepared using NaBr.
Sodium bromide is used in conjunction with chlorine as a disinfectant for hot tubs and swimming pools.[13]
Because of its highsolubility in water (943.2 g/L or 9.16 mol/L, at 25 °C) sodium bromide is used to prepare densedrilling fluids used inoil wells to compensate a possible overpressure arising in the fluid column and to counteract the associated trend toblow out. The presence of the sodiumcation also causes thebentonite added to the drilling fluid to swell, while the highionic strength induces bentoniteflocculation.[14]
NaBr has a very low toxicity with an oralLD50 estimated at 3.5 g/kg for rats.[6] However, this is a single-dose value. Bromide ions are a cumulative toxin with a relatively longbiological half-life (in excess of a week in humans): seepotassium bromide.
Human consumption can lead tobromism.[15]
