Sodium bifluoride is the

inorganic compound In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as '' inorganic chemist ...

with the formula . It is a salt of sodium cation () and bifluoride anion (). It is a white, water-soluble solid that decomposes upon heating . Sodium bifluoride is non-flammable, hygroscopic, and has a pungent smell. Sodium bifluoride has a number of applications in industry.

Reactions

Sodium bifluoride dissociates to

hydrofluoric acid Hydrofluoric acid is a Solution (chemistry), solution of hydrogen fluoride (HF) in water. Solutions of HF are colourless, acidic and highly Corrosive substance, corrosive. It is used to make most fluorine-containing compounds; examples include th ...

and sodium fluoride: : The reverse of this reaction is employed to remove HF from elemental fluorine () produced by electrolysis. This equilibrium is manifested when the salt is dissolved and when the solid is heated. Characteristic of other bifluorides, it reacts with

acid In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a sequ ...

s to give HF. Illustrative is its reaction with bisulfate to form

sodium sulfate Sodium sulfate (also known as sodium sulphate or sulfate of soda) is the inorganic compound with formula Na2SO4 as well as several related hydrates. All forms are white solids that are highly soluble in water. With an annual production of 6 milli ...

and hydrogen fluoride.

Strong base In chemistry, there are three definitions in common use of the word base, known as Arrhenius bases, Brønsted bases, and Lewis bases. All definitions agree that bases are substances that react with acids, as originally proposed by G.-F. Rou ...

s deprotonate bifluoride. For example,

calcium hydroxide Calcium hydroxide (traditionally called slaked lime) is an inorganic compound with the chemical formula Ca( OH)2. It is a colorless crystal or white powder and is produced when quicklime (calcium oxide) is mixed or slaked with water. It has m ...

gives calcium fluoride.

Production

Sodium bifluoride is produced by neutralizing waste

hydrogen fluoride Hydrogen fluoride (fluorane) is an inorganic compound with the chemical formula . This colorless gas or liquid is the principal industrial source of fluorine, often as an aqueous solution called hydrofluoric acid. It is an important feedstock i ...

, 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: : : Sodium bifluoride reacts with water or moist skin to produce

. 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 base In chemistry, there are three definitions in common use of the word base, known as Arrhenius bases, Brønsted bases, and Lewis bases. All definitions agree that bases are substances that react with acids, as originally proposed by G.-F. Rou ...

s, metal, water, or glass. Sodium bifluoride also engages in violent reactions with chromyl chloride, nitric acid, red phosphorus, sodium peroxide, diethyl sulfoxide, and diethylzinc.

Applications

The main role of sodium bifluoride is as a precursor to sodium fluoride, millions of tons of which are produced annually.

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 A brick is a type of block used to build walls, pavements and other elements in masonry construction. Properly, the term ''brick'' denotes a block composed of dried clay, but is now also used informally to denote other chemically cured cons ...

, stone, ceramics, and masonry. It is also used to etch glass. Another application of sodium bifluoride is in the

chemical industry The chemical industry comprises the companies that produce industrial chemicals. Central to the modern world economy, it converts raw materials (oil, natural gas, air, water, metals, and minerals) into more than 70,000 different products. The ...

. Other applications of the compound involve the galvanization of baths and

pest Pest or The Pest may refer to: Science and medicine * Pest (organism), an animal or plant deemed to be detrimental to humans or human concerns ** Weed, a plant considered undesirable * Infectious disease, an illness resulting from an infection ** ...

control. Sodium bifluoride's biological applications include the preservation of zoological and

anatomical Anatomy () is the branch of biology concerned with the study of the structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old science, having it ...

samples. Other applications of sodium bifluoride include neutralizers of

laundry Laundry refers to the washing of clothing and other textiles, and, more broadly, their drying and ironing as well. Laundry has been part of history since humans began to wear clothes, so the methods by which different cultures have dealt with t ...

-rinse.

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 Electroplating, also known as electrochemical deposition or electrodeposition, is a process for producing a metal coating on a solid substrate through the reduction of cations of that metal by means of a direct electric current. The part to be ...

. The compound also aids in increasing the corrosion of resistance of some magnesium alloys.

Precautions

Sodium bifluoride is corrosive and an irritant upon contact with skin and can cause

blister A blister is a small pocket of body fluid (lymph, serum, plasma, blood, or pus) within the upper layers of the skin, usually caused by forceful rubbing (friction), burning, freezing, chemical exposure or infection. Most blisters are filled wi ...

ing 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. It can take between 0 and 24 hours for the effects of sodium bifluoride poisoning to be noticeable. Exposure to sodium bifluoride repeatedly or over a long time can result in fluorosis. Sodium bifluoride is not known to be carcinogenic.

Biological and environmental role

Sodium bifluoride does not bioaccumulate. It typically only remains in the environment for several days.

References

{{Hydrogen compounds Fluorine compounds Sodium compounds Toxins Hydrogen compounds Bifluorides