sodium hydroxide

a white deliquescent strongly alkaline solid used in the manufacture of rayon, paper, aluminium, soap, and sodium compounds. Formula: NaOH

Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005

sodium hydroxide

[′sōd·ē·əm hī′dräk‚sīd]

(inorganic chemistry)

NaOH White, deliquescent crystals; absorbs carbon dioxide and water from air; soluble in water, alcohol, and glycerol; melts at 318°C; used as an analytical reagent and chemical intermediate, in rubber reclaiming and petroleum refining, and in detergents. Also known as sodium hydrate.

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Sodium Hydroxide

(caustic soda, soda lye), NaOH, a caustic alkali; colorless crystals. Density, 2.13 g/cm³; melting point, 320°C. The industrial product is an opaque, white solid mass with a radial fracture. Sodium hydroxide is hygroscopic; a large amount of heat is liberated upon its reaction with water. Aqueous solutions of NaOH exhibit a strong alkaline reaction. The solubility of sodium hydroxide in water is 52.2 percent at 20°C and 75.8 percent at 80°C. It forms crystal hydrates, such as NaOH-H₂O, which is stable at ordinary temperatures (12.3°-61.8°C). Upon exposure to air, NaOH absorbs CO₂ and is converted into sodium carbonate. Sodium hydroxide has a destructive effect on skin, paper, and other materials; even very small quantities of NaOH cause extremely severe damage upon contact with the eyes.

Sodium hydroxide is prepared by electrolysis of NaCl solutions or by boiling a Na₂ CO₃solution with milk of lime: Na₂C0₃+ Ca (OH)₂ CaC0₃+ 2NaOH. The sodium hydroxide solution is evaporated, and the residue is heated to the melting point and then poured into molds. Electrolysis yields chlorine in addition to NaOH. Sodium hydroxide is one of the main products of the modern chemical industry; it is widely used both in the chemical industry and in many other sectors.

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References in periodicals archive

Which are the key product types in the Oman sodium hydroxide market?

Oman Sodium Hydroxide Market Growth Expected to be Around 5% During the Forecast Period, 2019-2024

Obstructive airway disease associated with occupational sodium hydroxide inhalation.

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Fish scale solutions were selected on the basis of the initial concentration of sodium hydroxide employed for dissolution of the same quantity of fish scales.

Investigation of the Effect of Base Strength on the Antifungal Activity and Chemical Composition of the Fish Scales Hydrolyzates

Addition of 0.01%, 0.025%, and 0.05% sodium hydroxide solutions decreased (P<0.05) the obtained mean values of Domic acidity, from 17[degrees]D in the negative control to 16[degrees]D, 13[degrees]D, and 10[degrees]D, respectively in the experimental aliquots.

Preservatives and neutralizing substances in milk: analytical sensitivity of official specific and nonspecific tests, microbial inhibition effect, and residue persistence in milk/Sustancias conservantes e neutralizantes no leite: sensibilidade analitica das provas oficiais especificas, provas inespecificas, inibicao microbiana e persistencia de residuos no leite

The other issue is under pressure cell that have the ability to produce liquid chlorine gas of electrolysis, the ability to produce sodium hydroxide 50% or solid sodium hydroxide.

Investigation of producing chlorine with electro dialysis method and the effect of operating parameters: a review

Reactive dyeing by pad-batch method: The lyocell fabric was padded with 10 g/l, 20 g/l and 30 g/l reactive dye, 2 g/l Drimagen E2R, 20 g/l sodium hydroxide (36oBe), 30 g/l sodium carbonate and 50 g/l urea.

EFFECT OF CAUSTICIZATION ON COLOUR STRENGTH (K/S) OF REACTIVE DYED LYOCELL FABRIC

But if, instead of making the blade thicker, we covered it with sodium carbonate, then the radiation increased again considerably; it became fifty percent stronger than with the platinum blade without any sodium hydroxide.

A note on the constitution of the Sun

The result showed sodium hydroxide caused to increase the fungal digestion of DM and NDF of rice straw and chitin content of media that indicator of increase of fungi growth, and the effect of 120 g/kg DM sodium hydroxide was more than 45 and 70 g/kg DM NaOH.

The effect of sodium hydroxide on in vitro disappearance of dry matter and neutral detergent fibre of rice straw by rumen anaerobic fungi

The sodium hydroxide and the sodium silicate solutions were first mixed with each other and stirred to obtain a homogeneous mixture of the solutions before adding them to the solids.

Geopolymer concrete: a concrete to be known more

At the ethanol factory, furthermore, a part of cellulose that is a raw material for fuel alcohol is poured in sodium hydroxide to produce sodium nitrate, which is used for removing calcium in the seawater and facilitating the molten-salt electrolysis of sodium or magnesium (Murahara and Seki, 2007).

Wind power and seawater, save corn from ethanol production: marine resources recovery and offshore integrated plant for sodium fuel, fresh water, ethanol, vegetable, and fish production with wind energy and seawater

"The treatment chemical used by the Town is sodium hydroxide, and the approval states that `alarms will be sent to a location monitored 24 hours a day,'" according to the DEP consent order.

Lye incident fines could top $34K; Town working to correct system's malfunction