Cov khoom ntshiab yog cov xim tsis muaj xim thiab pob tshab. Qhov ceev yog 2.130g / cm3. Lub melting point yog 318.4 degree. Kub taw tes 1390 degree. Cov khoom lag luam muaj me me ntawm sodium chloride thiab sodium carbonate, uas yog dawb opaque crystals. Muaj cov blocks, flakes, granules thiab rods, thiab lwm yam. Formula hnyav 39.997. Sodium hydroxide tuaj yeem siv los ua tus neeg saib xyuas alkaline hauv kev kho dej, soluble hauv ethanol thiab glycerol; insoluble nyob rau hauv propanol thiab ether. Nws reacts nrog halogens xws li chlorine, bromine thiab iodine los ntawm disproportionation. Neutralizes nrog acids los tsim ntsev thiab dej.
Sodium hydroxide tau ntev tau paub tias yog cov khoom alkaline. Xyoo 1787, tus kws kho mob Nicolas Leblanc (1762-1806) tau tsim cov txheej txheem tsim nyog rau kev npaj sodium hydroxide los ntawm cov ntsev ntsev, thiab ua cov khoom loj. Xyoo 1887, Swedish chemist Arrhenius tau tsim txoj kev xav ntawm acid-base ionization (uas yog, acid-base theory of aqueous solutions). Tag nrho cov anions tsim los ntawm ionization yog hydroxide ions.
Txij thaum ntawd los, alkalinity ntawm sodium hydroxide tau raug txhais kom meej. Ntshiab anhydrous sodium hydroxide yog dawb translucent, crystalline khoom. Sodium hydroxide yog soluble heev hauv dej, thiab nws cov solubility nce nrog qhov kub thiab txias. Nws tuaj yeem tso cua sov ntau thaum nws yaj. Ntawm 288K, nws cov kua dej txaus siab tuaj yeem ncav cuag 16.4mol / L (1: 1). Nws cov tshuaj aqueous muaj astringency thiab greasy xav, cov tshuaj muaj zog alkaline, tuaj yeem hnov mob nrog acidic tshuaj, thiab muaj tag nrho cov khoom ntawm alkali. Muaj ob hom caustic soda muaj nyob rau hauv kev ua lag luam: khoom thiab ua kua: ntshiab khoom caustic soda yog dawb, hauv thaiv, flake, pas nrig, granular, thiab brittle; ntshiab kua caustic soda yog tsis muaj xim thiab pob tshab kua.
Sodium hydroxide, cov tshuaj formula yog NaOH, feem ntau hu ua caustic soda, caustic soda, caustic soda, yog ib tug muaj zog corrosive alkali, feem ntau nyob rau hauv cov duab ntawm flakes los yog blocks, yooj yim soluble nyob rau hauv dej (soluble nyob rau hauv dej, exothermic) thiab nws cov ntaub ntawv. ib qho alkaline tov thiab muaj deliquescence, uas yog ib qho yooj yim rau nqus dej vapor (deliquescence) thiab carbon dioxide (deliquescence) nyob rau hauv cov huab cua. NaOH yog ib qho tshuaj tseem ceeb hauv cov chaw kuaj tshuaj, thiab nws kuj yog ib qho tshuaj lom neeg.
