Sodium bifluoride
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Names | |
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IUPAC name Sodium bifluoride | |
Other names
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3D model (JSmol) |
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ECHA InfoCard | 100.014.190 ![]() |
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UNII |
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UN number | 2439 |
CompTox Dashboard (EPA) |
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InChI
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Properties | |
Chemical formula | Na[HF2] |
Molar mass | 61.995 g·mol−1 |
Appearance | white solid |
Density | 2.08 g/cm3 |
Melting point | 160 °C (320 °F; 433 K) (decomposes) |
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Danger | |
Hazard statements | H301, H314 |
Precautionary statements | P260, P264, P270, P280, P301+P310, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P310, P321, P330, P363, P405, P501 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references |
Sodium bifluoride is the inorganic compound with the formula Na[HF2]. It is a salt of sodium cation (Na+) and bifluoride anion ([HF2]−). It is a white, water-soluble solid that decomposes upon heating .[2] Sodium bifluoride is non-flammable, hygroscopic, and has a pungent smell.[3] Sodium bifluoride has a number of applications in industry.
Reactions
Sodium bifluoride dissociates to hydrofluoric acid and sodium fluoride:
- Na[HF2] ⇌ HF + NaF
The reverse of this reaction is employed to remove HF from elemental fluorine (F2) produced by electrolysis.[4] This equilibrium is manifested when the salt is dissolved and when the solid is heated. Characteristic of other bifluorides, it reacts with acids to give HF. Illustrative is its reaction with bisulfate to form sodium sulfate and hydrogen fluoride.
Strong bases deprotonate bifluoride. For example, calcium hydroxide gives calcium fluoride.[5]
Production
Sodium bifluoride is produced by neutralizing waste hydrogen fluoride, which results from the production of superphosphate fertilizers. Typical bases are sodium carbonate and sodium hydroxide. The process occurs in two steps, illustrated with the hydroxide:[4]
- HF + NaOH → NaF + H2O
- HF + NaF → Na[HF2]
Sodium bifluoride reacts with water or moist skin to produce hydrofluoric acid. It also gives off hydrofluoric acid and hydrogen gas when it is heated to a gaseous state. The chemical can decompose upon contact with strong acids, strong bases, metal, water, or glass.[3] Sodium bifluoride also engages in violent reactions with chromyl chloride, nitric acid, red phosphorus, sodium peroxide, diethyl sulfoxide, and diethylzinc.[6]
Applications
The main role of sodium bifluoride is as a precursor to sodium fluoride, millions of tons of which are produced annually.[4]
Cleaning agents and laundry sours
The compound also has applications in cleaning, capitalizing on the affinity of fluoride for iron and silicon oxides. For example, formulations of sodium bifluoride are used for cleaning brick, stone, ceramics, and masonry. It is also used to etch glass.[3] Another application of sodium bifluoride is in the chemical industry.[7] Other applications of the compound involve the galvanization of baths and pest control.[8] Sodium bifluoride's biological applications include the preservation of zoological and anatomical samples.[9]
Other applications of sodium bifluoride include as laundry sours.[4]
Other uses
Sodium bifluoride has a role in the process that is used to plate metal cans.
Sodium bifluoride also aids in the precipitation of calcium ions during the process of nickel electroplating. The compound also aids in increasing the corrosion of resistance of some magnesium alloys.[10]
Precautions
Sodium bifluoride is corrosive and an irritant upon contact with skin and can cause blistering and inflammation. It is extremely dangerous to ingest. If the compound is exposed to the eyes, blindness and corneal damage can result. Ingestion of sodium bifluoride dust can cause burning, coughing, and sneezing, as a result of irritating the gastrointestinal and respiratory tracts. Exposure of the compound to the eyes can cause redness, itching, and watering. In severe cases, exposure to sodium bifluoride can result in death.[11] It can take between 0 and 24 hours for the effects of sodium bifluoride poisoning to be noticeable.[3]
Exposure to sodium bifluoride repeatedly or over a long time can result in fluorosis. Sodium bifluoride is not known to be carcinogenic.[3]
Biological and environmental role
Sodium bifluoride does not bioaccumulate. It typically only remains in the environment for several days.[3]
References
- ^ Product Safety Summary (PDF), retrieved June 17, 2013
- ^ Perry, Dale L.; Handbook of Inorganic Compounds; CRC Press (2011); page 381; [1]
- ^ a b c d e f Product Safety Data Sheet (PDF), retrieved June 17, 2013
- ^ a b c d Aigueperse, Jean; Mollard, Paul; Devilliers, Didier; Chemla, Marius; Faron, Robert; Romano, Renée; Cuer, Jean Pierre (2005), "Fluorine Compounds, Inorganic", in Ullmann (ed.), Encyclopedia of Industrial Chemistry, Weinheim: Wiley-VCH, doi:10.1002/14356007.a11_307
- ^ Sodium Bifluoride NaHF2, retrieved June 28, 2013
- ^ Richard P. Pohanish; Stanley A. Greene (August 25, 2009), Wiley Guide to Chemical Incompatibilities, John Wiley & Sons, ISBN 9780470523308, retrieved June 29, 2013
- ^ http://www.solvaychemicals.us/SiteCollectionDocuments/sds/P19043-USA.pdf[permanent dead link]
- ^ Sodium Bifluoride, October 14, 2010, retrieved June 26, 2013
- ^ Sodium Bifluorite, Solid, 2012, retrieved June 26, 2013
- ^ Alain Tressaud, ed. (April 9, 2010), Functionalized Inorganic Fluorides: Synthesis, Characterization and Properties of Nanostructured Solids, John Wiley & Sons, ISBN 9780470660751, retrieved July 1, 2013
- ^ Material Safety Data Sheet Sodium bifluoride MSDS, October 9, 2005, retrieved June 13, 2013
- v
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HF | He | |||||||||||||||||
LiF | BeF2 | BF BF3 B2F4 | CF4 CxFy | NF3 N2F4 | OF OF2 O2F2 O2F | F− | Ne | |||||||||||
NaF | MgF2 | AlF AlF3 | SiF4 | P2F4 PF3 PF5 | S2F2 SF2 S2F4 SF4 S2F10 SF6 | ClF ClF3 ClF5 | HArF ArF2 | |||||||||||
KF | CaF2 | ScF3 | TiF3 TiF4 | VF2 VF3 VF4 VF5 | CrF2 CrF3 CrF4 CrF5 CrF6 | MnF2 MnF3 MnF4 | FeF2 FeF3 | CoF2 CoF3 | NiF2 NiF3 | CuF CuF2 | ZnF2 | GaF3 | GeF4 | AsF3 AsF5 | SeF4 SeF6 | BrF BrF3 BrF5 | KrF2 KrF4 KrF6 | |
RbF | SrF2 | YF3 | ZrF4 | NbF4 NbF5 | MoF4 MoF5 MoF6 | TcF6 | RuF3 RuF4 RuF5 RuF6 | RhF3 RhF5 RhF6 | PdF2 Pd[PdF6] PdF4 PdF6 | AgF AgF2 AgF3 Ag2F | CdF2 | InF3 | SnF2 SnF4 | SbF3 SbF5 | TeF4 TeF6 | IF IF3 IF5 IF7 | XeF2 XeF4 XeF6 XeF8 | |
CsF | BaF2 | * | LuF3 | HfF4 | TaF5 | WF4 WF6 | ReF6 ReF7 | OsF4 OsF5 OsF6 OsF 7 OsF8 | IrF3 IrF5 IrF6 | PtF2 Pt[PtF6] PtF4 PtF5 PtF6 | AuF AuF3 Au2F10 AuF5·F2 | HgF2 Hg2F2 HgF4 | TlF TlF3 | PbF2 PbF4 | BiF3 BiF5 | PoF4 PoF6 | At | RnF2 RnF6 |
Fr | RaF2 | ** | Lr | Rf | Db | Sg | Bh | Hs | Mt | Ds | Rg | Cn | Nh | Fl | Mc | Lv | Ts | Og |
↓ | ||||||||||||||||||
* | LaF3 | CeF3 CeF4 | PrF3 PrF4 | NdF3 | PmF3 | SmF2 SmF3 | EuF2 EuF3 | GdF3 | TbF3 TbF4 | DyF3 | HoF3 | ErF3 | TmF2 TmF3 | YbF2 YbF3 | ||||
** | AcF3 | ThF4 | PaF4 PaF5 | UF3 UF4 UF5 UF6 | NpF3 NpF4 NpF5 NpF6 | PuF3 PuF4 PuF5 PuF6 | AmF3 AmF4 AmF6 | CmF3 | Bk | Cf | Es | Fm | Md | No |
- AgPF6
- KAsF6
- LiAsF6
- NaAsF6
- HPF6
- HSbF6
- NH4PF6
- KPF6
- KSbF6
- LiPF6
- NaPF6
- NaSbF6
- TlPF6
- Cs2AlF5
- Li3AlF6
- K3AlF6
- Na3AlF6
and pseudohalogenides
- BaSiF6
- BaGeF6
- (NH4)2SiF6
- Na2[SiF6]
- K2[SiF6]
- Li2GeF6
- Li2SiF6
- CBrF3
- CBr2F2
- CBr3F
- CClF3
- CCl2F2
- CCl3F
- CF2O
- CF3I
- CHF3
- CH2F2
- CH3F
- C2Cl3F3
- C2H3F
- C6H5F
- C7H5F3
- C15F33N
- C3H5F
- C6H11F
lanthanide, actinide, ammonium
- VOF3
- CrOF4
- CrF2O2
- NH4F
- (NH4)2ZrF6
- CsXeF7
- Li2TiF6
- Li2ZrF6
- K2TiF6
- Rb2TiF6
- Na2TiF6
- Na2ZrF6
- K2NbF7
- K2TaF7
- K2ZrF6
- UO2F2
- FNO
- FNO2
- FNO3
- KHF2
- NaHF2
- NH4HF2
and iodosyl
- F2OS
- F3OP
- PSF3
- IOF3
- IO3F
- IOF5
- IO2F
- IO2F3