Caustic soda yog dab tsi? Qhov ntom ntawm sodium hydroxide

2024 Tus sau: Angel Austin | [email protected]. Kawg hloov kho: 2024-01-02 17:48

Nyob hauv lub ntiaj teb niaj hnub no, lub neej yeej ua tsis tau yam tsis muaj tshuaj lom neeg uas tshwm sim txhua qhov chaw thiab muaj txiaj ntsig thiab txaus ntshai. Raws li lub sij hawm lub sij hawm ntawm chemical ntsiab lus ntawm D. I. Mendeleev, hlau ntawm lub thib 1 pab pawg neeg ntawm lub ntsiab subgroup, uas muaj xws li sodium (Na), react hnyav nrog dej, tsim alkalis - tshuaj active tshuaj.

Lub tswvyim ntawm alkalis

Cov dej-soluble hydroxides ntawm cov hlau nquag - alkalis - cov tshuaj caustic thiab txaus ntshai heev. Lawv yog cov tawv thiab dawb hauv cov xim. Dissolving hauv dej, cov hauv paus no tso cua sov. Alkalis kuj muaj peev xwm ua kom puas daim tawv nqaij, ntoo, ntaub, vim lawv tau txais lub npe tsis tseem ceeb "caustic", uas feem ntau tsuas yog siv rau alkali hlau hydroxides. Qhov zoo tshaj plaws alkalis muaj xws li hydroxides ntawm sodium (NaOH), poov tshuaj (KOH), lithium (LiOH), barium (Ba(OH) _{2), cesium (CsOH), calcium. (Ca(OH)}2_{) and some others.}

Sodium hydroxide: yam ntxwv

Caustic soda yog qhov tsis tseem ceebLub npe ntawm sodium hydroxide - ib qho ntawm feem ntau alkalis. Nws belongs rau cov tshuaj txaus ntshai, vim tias nws yooj yim corrodes tib neeg cov tawv nqaij, yog li koj yuav tsum ua raws li qhov tsim nyog ntsuas kev nyab xeeb thaum ua haujlwm nrog nws. Tsis tas li, sodium hydroxide qee zaum hu ua caustic soda, lossis caustic. Zoo li tag nrho lwm cov alkalis, nws cuam tshuam zoo nrog dej nrog kev tso tawm ntawm tshav kub thiab yog dawb, hygroscopic, uas yog, muaj peev xwm nqus dej vapor los ntawm huab cua, compound. Qhov ceev ntawm caustic soda yog 2.13 g / cm³.

Reactivity

Caustic soda tov tuaj yeem nkag mus rau hauv cov tshuaj tiv thaiv ntau yam, tsim lwm yam tshuaj.

1. Thaum cov tshuaj no ua rau cov kua qaub, ntsev thiab dej ib txwm tsim:

NaOH + HCl=NaCl₂ + H_2O.

2. Caustic soda muaj peev xwm hnov mob nrog acidic thiab amphoteric hlau oxides (hauv kev daws thiab thaum fused), kuj tsim cov ntsev thiab dej sib xws:

• 2NaOH + SO₃=Na₂SO₄ + H ₂O (SO_{3 - acid oxide);}
• 2NaOH + ZnO=Na₂ZnO₂ + H_{2O (ZnO – amphoteric oxide, qhov tshuaj tiv thaiv no tshwm sim los ntawm fusion thiab cua sov).}

Thaum sodium hydroxide reacts nrog amphoteric oxide tov, soluble complex ntsev yog tsim.

3. Cov tshuaj tiv thaiv ntawm alkali nrog amphoteric hydroxides kuj ua rau tsim cov yaj los yog complex sodium ntsev, nyob ntawm seb nws cov mob.

4. Los ntawm reacting lub caustic nrog ntsev, sodium thiab coj cov dej-insoluble hydroxide tau.

• 2NaOH + MgCl₂=2NaCl + Mg(OH)_{2 (magnesium hydroxide yog dej-insoluble base).}

5. Sodium hydroxide kuj tuaj yeem ua rau cov hlau tsis muaj hlau, xws li sulfur lossis halogens los tsim cov tshuaj sodium ntsev, nrog rau cov hlau amphoteric los tsim cov ntsev, hlau thiab tooj liab.

• 3S + 6NaOH=2Na₂S + Na₂SO₄ + 3H _2O.

6. Caustic soda kuj muaj peev xwm cuam tshuam nrog cov organic tshuaj, piv txwv li: esters, amides, polyhydric alcohols.

• 2C₂H₆O₂ + 2NaOH=C₂ H₄O₂Na₂ + 2H_{2 O (cov khoom siv tshuaj tiv thaiv yog sodium cawv).}

Tau txais

Muaj ntau txoj hauv kev tsim cov dej qab zib caustic hauv kev lag luam, cov khoom tseem ceeb yog tshuaj thiab electrochemical.

thawj txoj kev yog ua raws ntau txoj hauv kev: pyrolysis, txiv qaub thiab ferrite.

1. Pyrolysis yog ua los ntawm calcining sodium carbonate ntawm qhov kub thiab txias (tsawg kawg 1000 degrees) nrog kev tsim ntawm sodium oxide thiab carbon dioxide. Tom ntej no, qhov tshwm sim txias oxide yog yaj nyob rau hauv dej, raws li qhov tshwm sim ntawm caustic soda tau txais.

• Na₂CO₃=Na₂O + CO _{2 (ntawm 1000 degrees);}
• Na₂O + H₂O=_2NaOH.

Qee lub sij hawm sodium bicarbonate siv es tsis txhob sodium carbonate, thiab cov txheej txheem yog li me ntsis nyuab dua.

2. Txoj kev ua kua qaub rau kev tsim sodium hydroxide muaj nyob rau hauv kev sib cuam tshuam ntawm sodium ntsev ntawm carbonic acid nrog calcium hydroxide (slaked txiv qaub) thaum rhuab mus rau qhov kub ntawm tsawg kawg yog 80 degrees. Raws li qhov tshwm sim ntawm qhov kev cuam tshuam no, cov kev daws teeb meem ntawm alkali thiab calcium carbonate (CaCO _{3) tau, uas yog lim los ntawm cov tshuaj tseem ceeb.}

• Na₂CO₃ + Ca(OH)₂=2NaOH + CaCO _3.

3. Txoj kev ferrite yog ua nyob rau hauv ob theem: ua ntej, dej qab zib yog fused nrog hlau oxide III ntawm qhov kub txog li 1200 degrees kom tau txais sodium ferrite, ces tom kawg yog kho nrog dej, ua rau alkali.

• Na₂CO₃ + Fe₂O₃ =2NaFeO₂ + CO_2;
• 2NaFeO₂ + 2H₂O=2NaOH + Fe₂O3H _2O.

Nyob rau hauv txoj kev siv hluav taws xob ntawm kev tau txais cov dej qab zib caustic, ob peb txoj hauv kev kuj tseem siv: electrolysis ntawm sodium chloride tov (NaCl), diaphragm, membrane thiab mercury method nrog cov kua cathode. Peb txoj hauv kev kawg no yog qhov nyuaj dua li thawj zaug, tab sis lawv txhua tus cuam tshuam nrog kev hla hluav taws xob los ntawm kev daws cov ntsev sib thooj, uas yog, nrog electrolysis.

Txoj kev siv ntau tshaj plaws rau kev tsim cov alkali yog cov electrolysis ntawm cov tshuaj halite, muaj cov dej roojntsev, raws li qhov tshwm sim ntawm cov tshuaj chlorine thiab hydrogen raug tso tawm ntawm anode thiab cathode, thiab sodium hydroxide tau txais:

• 2NaCl + 2H₂O=H₂ + Cl_{2 + 2NaOH.}

Hauv chav kuaj, caustic soda kuj yog tsim los ntawm cov txheej txheem tshuaj, tab sis diaphragm thiab membrane txoj kev siv feem ntau.

Daim ntawv thov

Caustic soda yog siv tsis tau tsuas yog nyob rau hauv ntau yam lag luam, tab sis kuj nyob rau hauv lub neej txhua hnub. Nws siv:

1. Nyob hauv kev tsim cov tshuaj ntxuav tes.
2. Rau cov kua qaub nruab nrab lossis ua cov khoom siv tshuaj lom neeg hauv kev lag luam tshuaj.
3. Rau ua biodiesel, uas yog ib puag ncig tus phooj ywg ntau dua li cov pa roj carbon monoxide.
4. Cov granules qhuav yog tsim los ntawm nws, nrog kev pab los ntawm kev ntxuav cov kav dej thiab cov dab dej los ntawm cov khoom noj khoom haus.
5. Caustic soda kuj tseem siv tau hauv kev tsim cov khoom noj xws li khob cij lossis cocoa. Nws yog siv los ua zaub mov ntxiv.
6. Nyob hauv cosmetology, cov khoom siv los tshem tawm cov tawv nqaij tuag.
7. Rau cov duab nrawm dua.
8. Technical caustic soda yog dav siv hauv tshuaj, petrochemical, roj refining, pulp thiab ntawv, mining, textile, zaub mov thiab ntau lwm yam lag luam.

Kev Tiv Thaiv

Caustic soda yog lub hauv paus muaj zog. Nws tuaj yeem yooj yim puas tsis tsuas yog cov ntaub so ntswg, tab sis kuj tib neeg cov tawv nqaij, uas yuav ua nrogkub hnyiab. Thaum ua hauj lwm nrog cov khoom no, tej yam kev ruaj ntseg yuav tsum tau ceev faj, uas yog:

• Yuav tsum hnav hnab looj tes tshwj xeeb, tsom iav kom tiv thaiv kev daws ntawm tes thiab qhov muag.
• Koj yuav tsum hnav khaub ncaws uas yuav tiv taus cov tshuaj sib xyaw thiab yuav tsis tso cai rau lawv nkag mus rau ntawm daim tawv nqaij ntawm lub cev. Feem ntau cov khaub ncaws zoo li no tau kho nrog PVC.