Science & Tech

sodium hydroxide

chemical compound
verifiedCite
While every effort has been made to follow citation style rules, there may be some discrepancies. Please refer to the appropriate style manual or other sources if you have any questions.
Select Citation Style
Feedback
Corrections? Updates? Omissions? Let us know if you have suggestions to improve this article (requires login).
Thank you for your feedback

Our editors will review what you’ve submitted and determine whether to revise the article.

Print
verifiedCite
While every effort has been made to follow citation style rules, there may be some discrepancies. Please refer to the appropriate style manual or other sources if you have any questions.
Select Citation Style
Feedback
Corrections? Updates? Omissions? Let us know if you have suggestions to improve this article (requires login).
Thank you for your feedback

Our editors will review what you’ve submitted and determine whether to revise the article.

Also known as: NaOH, caustic soda
sodium hydroxide
sodium hydroxide
Also called:
caustic soda or lye
Related Topics:
alkali
hydroxide

sodium hydroxide (NaOH), a corrosive white crystalline solid that contains the Na+ (sodium) cation and the OH (hydroxide) anion. It readily absorbs moisture until it dissolves. Sodium hydroxide is the most widely used industrial alkali and is often used in drain and oven cleaners. It is highly corrosive to animal and vegetable tissue. The alkaline solutions it forms when dissolved in water neutralize acids in various commercial processes. In petroleum refining, it removes sulfuric and organic acids. In soapmaking, it acts on natural fats or oils, such as tallow or vegetable oil, to produce sodium fatty acid salt (soap) and glycerin (or glycerol); this saponification reaction is the basis for all soapmaking. In papermaking, sodium hydroxide is used to break down wood into pulp. Solutions of NaOH are used in the treatment of cellulose and in the manufacture of many chemicals.

The Editors of Encyclopaedia BritannicaThis article was most recently revised and updated by Erik Gregersen.