Sodium hydroxide
Sodium hydroxide, uas nws cov tshuaj formula yog NaOH, feem ntau hu ua caustic soda, caustic soda thiab caustic soda. Thaum yaj, nws emits ammonia tsw. Nws yog ib tug muaj zog causticalkali, uas yog feem ntau nyob rau hauv flake los yog granular daim ntawv. Nws yog yooj yim soluble nyob rau hauv dej (thaum yaj nyob rau hauv dej, nws muab tawm cua sov) thiab ua alkaline kua. Tsis tas li ntawd, nws yog deliquescent thiab yooj yim absorbs dej vapor (deliquescence) thiab carbon dioxide (deterioration) hauv huab cua. NaOH yog ib qho ntawm cov tshuaj tsim nyog hauv cov chaw sim tshuaj, thiab nws kuj yog ib qho ntawm cov tshuaj lom neeg. Cov khoom ntshiab yog xim tsis muaj xim thiab pob tshab siv lead ua. Qhov ceev 2.130 g / cm3 Melting point 318.4 ℃. Kub taw tes yog 1390 ℃. Cov khoom lag luam muaj me me ntawm sodium chloride thiab sodium carbonate, uas yog dawb thiab opaque crystals. Muaj blocky, flaky, granular thiab qws-puab. Hom kom muaj nuj nqis 40.01
Sodium hydroxidetuaj yeem siv ua alkaline tu tus neeg saib xyuas hauv kev kho dej, uas yog yaj hauv ethanol thiab glycerol; Insoluble hauv propanol thiab ether. Nws kuj corrodes carbon thiab sodium ntawm qhov kub thiab txias. Disproportionation cov tshuaj tiv thaiv nrog halogen xws li chlorine, bromine thiab iodine. Neutralize nrog acids tsim ntsev thiab dej.
Lub cev muaj zog ntawm folding
Sodium hydroxide yog cov dawb translucent crystalline khoom. Nws cov tshuaj aqueous muaj astringent saj thiab satiny xav.
Folding deliquescence Nws yog deliquescent nyob rau hauv cov huab cua.
Folding dej nqus
Khoom alkali yog hygroscopic heev. Thaum raug huab cua, nws absorbs dej molecules nyob rau hauv cov huab cua, thiab thaum kawg dissolves tag nrho rau hauv tov, tab sis kua sodium hydroxide tsis muaj hygroscopicity.
Folding solubility
Folding alkalinity
Sodium hydroxide yuav tag nrho dissociate rau hauv sodium ions thiab hydroxide ions thaum yaj hauv dej, yog li nws muaj qhov dav dav ntawm alkali.
Nws tuaj yeem nqa tawm cov tshuaj tiv thaiv acid-base neutralization nrog rau cov tshuaj protonic acid (uas kuj yog cov tshuaj tiv thaiv ob npaug ntawm cov decomposition):
NaOH + HCl = NaCl + H₂O
2 NaOH + H₂SO₄ = Na₂SO₄ + 2H₂O
NaOH + HNO₃ = NaO₃ + H₂O
Ib yam li ntawd, nws txoj kev daws teeb meem tuaj yeem dhau los ua ob qhov kev sib xyaw ua ke nrog ntsev tov:
NaOH + NH₄Cl = NaCl + NH₃·H₂O
2 NaOH + CuSO₄ = Cu(OH)₂↓ + Na₂SO₄
2NaOH+MgCl₂ = 2NaCl+Mg(OH)₂↓
Folding saponification cov tshuaj tiv thaiv
Hauv ntau cov tshuaj tiv thaiv organic, sodium hydroxide kuj ua lub luag haujlwm zoo ib yam li catalyst, ntawm cov neeg sawv cev tshaj plaws yog saponification:
RCOOR' + NaOH = RCOONa + R'OH
Kaw lwm yam
Qhov laj thawj yog vim li cas sodium hydroxide yooj yim deteriorates rau hauv sodium carbonate (Na₂CO₃) hauv huab cua yog vim huab cua muaj carbon dioxide (co):
2 NaOH + CO₂ = Na₂CO₃ + H₂O
Yog tias cov pa roj carbon dioxide ntau dhau los ua ntu zus, sodium bicarbonate (NaHCO₃), feem ntau hu ua baking soda, yuav raug tsim tawm, thiab qhov sib npaug ntawm cov tshuaj tiv thaiv yog raws li hauv qab no:
Na₂CO₃ + CO₂ + H₂O = 2NaHCO₃
Ib yam li ntawd, sodium hydroxide tuaj yeem ua rau cov kua qaub oxides xws li silicon dioxide (SiO₂) thiab sulfur dioxide (SO):
2 NaOH + SiO₂ = Na₂SiO₃ + H₂O
2 NaOH+SO (trace) = Na₂SO₃+H₂O
NaOH + SO₂ (ntau dhau) = NaHSO₃ (tsim NASO thiab dej ua haujlwm nrog SO ntau dhau los tsim cov nahSO)
