Sodium hydroxide

caustic sodaNaOHsodiumlyesodasodium hydroxide solutionalkali metal hydroxidesCausticsoda lyeE524
Sodium hydroxide, also known as lye and caustic soda, is an inorganic compound with the formula NaOH.wikipedia
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Lye

alkaline liquorlye wateroven cleaner
Sodium hydroxide, also known as lye and caustic soda, is an inorganic compound with the formula NaOH.
"Lye" is commonly an alternative name of sodium hydroxide (NaOH) or historically potassium hydroxide (KOH), though the term "lye" refers most commonly to sodium hydroxide.

Sodium

NaNa + sodium ion
It is a white solid ionic compound consisting of sodium cations and hydroxide anions.
Sodium was first isolated by Humphry Davy in 1807 by the electrolysis of sodium hydroxide.

Hydroxide

OHhydroxide ionOH −
It is a white solid ionic compound consisting of sodium cations and hydroxide anions.
Sodium hydroxide is a multi-million-ton per annum commodity chemical.

Base (chemistry)

basebasicbases
Sodium hydroxide is a highly caustic base and alkali that decomposes proteins at ordinary ambient temperatures and may cause severe chemical burns.
Examples of bases are the hydroxides of the alkali metals and the alkaline earth metals (NaOH, Ca(OH) 2, etc.—see alkali hydroxide and alkaline earth hydroxide).

Drain cleaner

Drain openeracidic drain cleanersalkaline versions
Sodium hydroxide is used in many industries: in the manufacture of pulp and paper, textiles, drinking water, soaps and detergents, and as a drain cleaner.
Alkaline drain openers primarily contain sodium hydroxide (lye) and some may contain potassium hydroxide.

Sodium chloride

NaClsaltroad salt
For example, when sodium hydroxide reacts with hydrochloric acid, sodium chloride is formed:
It is the starting point for the chloralkali process, the industrial process to produce chlorine and sodium hydroxide, according to the chemical equation

Chemical burn

chemical burnschemicalacid burn
Sodium hydroxide is a highly caustic base and alkali that decomposes proteins at ordinary ambient temperatures and may cause severe chemical burns.
Common sources of chemical burns include sulfuric acid (H 2 SO 4 ), hydrochloric acid (HCl), sodium hydroxide (NaOH), lime (CaO), silver nitrate (AgNO 3 ), and hydrogen peroxide (H 2 O 2 ).

Potassium hydroxide

KOHcaustic potashpotassium
However, the limited solubility of sodium hydroxide in organic solvents means that the more soluble potassium hydroxide (KOH) is often preferred.
Along with sodium hydroxide (NaOH), this colorless solid is a prototypical strong base.

Titration

titranttitratetitrated
Such acid-base reactions can also be used for titrations.
For example, the titration curve for the titration between oxalic acid (a weak acid) and sodium hydroxide (a strong base) is pictured.

Chloralkali process

chlor-alkalichloralkalielectrolysis of brine
Sodium hydroxide is industrially produced as a 50% solution by variations of the electrolytic chloralkali process.
It is the technology used to produce chlorine and sodium hydroxide (lye/caustic soda), which are commodity chemicals required by industry.

Alkali

alkalinealkalisalkalinity
Sodium hydroxide is a highly caustic base and alkali that decomposes proteins at ordinary ambient temperatures and may cause severe chemical burns.

Olin Corporation

OlinOlin Mathieson Chemical CorporationOlin Industries
Other major US producers include Oxychem, Westlake, Olin, Shintek and Formosa.
The Olin Corporation is an American manufacturer of ammunition, chlorine, and sodium hydroxide.

Acid–base reaction

acid-base reactionacid-baseacid-base chemistry
Such acid-base reactions can also be used for titrations.
For example, the reaction of hydrochloric acid, HCl, with sodium hydroxide, NaOH, solutions produces a solution of sodium chloride, NaCl, and some additional water molecules.

Corrosive substance

corrosivecausticcaustics
Sodium hydroxide is a highly caustic base and alkali that decomposes proteins at ordinary ambient temperatures and may cause severe chemical burns.

Pulp (paper)

pulpwood pulppaper pulp
Sodium hydroxide is used in many industries: in the manufacture of pulp and paper, textiles, drinking water, soaps and detergents, and as a drain cleaner.
Wood chips can be pre-treated with sodium carbonate, sodium hydroxide, sodium sulfate and other chemicals prior to refining with equipment similar to a mechanical mill.

Ethanol

alcoholbioethanolethyl alcohol
Pure sodium hydroxide is a colorless crystalline solid that melts at 318 C without decomposition, and with a boiling point of 1388 C. It is highly soluble in water, with a lower solubility in polar solvents such as ethanol and methanol.
The polar nature of the hydroxyl group causes ethanol to dissolve many ionic compounds, notably sodium and potassium hydroxides, magnesium chloride, calcium chloride, ammonium chloride, ammonium bromide, and sodium bromide.

Chlorine

Clchlorine gaschlorinated
Chlorine gas is also produced in this process.
Near the end of the nineteenth century, E. S. Smith patented a method of sodium hypochlorite production involving electrolysis of brine to produce sodium hydroxide and chlorine gas, which then mixed to form sodium hypochlorite.

Neutralization (chemistry)

neutralizationneutralizeneutralized
In general, such neutralization reactions are represented by one simple net ionic equation:
For example, sodium hydroxide, NaOH, is a strong base.

Hygroscopy

hygroscopicdeliquescenthygroscopicity
However, sodium hydroxide is not used as a primary standard because it is hygroscopic and absorbs carbon dioxide from air.
Zinc chloride and calcium chloride, as well as potassium hydroxide and sodium hydroxide (and many different salts), are so hygroscopic that they readily dissolve in the water they absorb: this property is called deliquescence.

Dow Chemical Company

Dow ChemicalDowThe Dow Chemical Company
In the United States, the major producer of sodium hydroxide is the Dow Chemical Company, which has annual production around 3.7 million tonnes from sites at Freeport, Texas, and Plaquemine, Louisiana.
Major products include ethylene glycol, caustic soda, chlorine, and vinyl chloride monomer (VCM, for making PVC).

Hydrolysis

hydrolyzedhydrolysehydrolyze
Sodium hydroxide can be used for the base-driven hydrolysis of esters (as in saponification), amides and alkyl halides.
It is the hydrolysis of a triglyceride (fat) with an aqueous base such as sodium hydroxide (NaOH).

Primary standard

primary frequency standardprimary frequency standardsPrimary standards
However, sodium hydroxide is not used as a primary standard because it is hygroscopic and absorbs carbon dioxide from air.

Kraft process

kraftkraft pulpingkraft pulp mill
Along with sodium sulfide, sodium hydroxide is a key component of the white liquor solution used to separate lignin from cellulose fibers in the kraft process.
The kraft process entails treatment of wood chips with a hot mixture of water, sodium hydroxide (NaOH), and sodium sulfide (Na 2 S), known as white liquor, that breaks the bonds that link lignin, hemicellulose, and cellulose.

Sodium carbonate

soda ashsodaNa 2 CO 3
Historically, sodium hydroxide was produced by treating sodium carbonate with calcium hydroxide in a metathesis reaction.
In cooking, it is sometimes used in place of sodium hydroxide for lyeing, especially with German pretzels and lye rolls.

Bayer process

Bayerextracting itprocess
It is used in the Bayer process of aluminium production.
In the Bayer process, bauxite ore is heated in a pressure vessel along with a sodium hydroxide solution (caustic soda) at a temperature of 150 to 200 °C.