Sodium bifluoride

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Sodium bifluoride
Names
IUPAC name
Sodium bifluoride
Other names
  • Sodium hydrogen fluoride
  • SBF[1]
  • Sodium acid fluoride
Identifiers
3D model (
JSmol
)
ChemSpider
ECHA InfoCard
 100.014.190 Edit this at Wikidata
EC Number
  • 215-608-3
UNII
UN number 2439
  • InChI=1S/F2H.Na/c1-3-2;/q-1;+1
    Key: WKYQUTKZJQOMHI-UHFFFAOYSA-N
  • [H-](F)F.[Na+]
Properties
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)
Hazards
GHS labelling:
GHS05: CorrosiveGHS06: Toxic
Danger
H301, H314
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).

Sodium bifluoride is the

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

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

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

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

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

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

  1. ^ Product Safety Summary (PDF), retrieved June 17, 2013
  2. ^ Perry, Dale L.; Handbook of Inorganic Compounds; CRC Press (2011); page 381; [1]
  3. ^ a b c d e f Product Safety Data Sheet (PDF), retrieved June 17, 2013
  4. ^
    doi:10.1002/14356007.a11_307
  5. ^ Sodium Bifluoride NaHF2, retrieved June 28, 2013
  6. ISBN 9780470523308
    , retrieved June 29, 2013
  7. ^ http://www.solvaychemicals.us/SiteCollectionDocuments/sds/P19043-USA.pdf[permanent dead link]
  8. ^ Sodium Bifluoride, October 14, 2010, retrieved June 26, 2013
  9. ^ Sodium Bifluorite, Solid, 2012, retrieved June 26, 2013
  10. ISBN 9780470660751
    , retrieved July 1, 2013
  11. ^ Material Safety Data Sheet Sodium bifluoride MSDS, October 9, 2005, retrieved June 13, 2013
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