Acetic acid - suav nrog glacial acetic acid - yog ib qho molecular (covalent) compound, tsis yog ionic.Kev sib xyaw ua ke- nce: nws ib nrab ionizes ib zaug yaj hauv dej, uas ua rau tib neeg xav tias nws yog ionic compound. Nws tsis yog - uas yog qhov tsis muaj zog acids coj tus cwj pwm hauv kev daws teeb meem.
Qhov tseeb ntawm cov qauv piav qhia ntau yam txog yuav ua li cas qhov sib xyaw no ua tau zoo: yog vim li cas nws sib tov dawb nrog dej thiab cawv, vim li cas nws nyuam qhuav ua hluav taws xob hauv daim ntawv ntshiab, thiab vim li cas nws thiaj li volatile piv rau cov khoom ruaj khov ionic.
Glacial Acetic Acid yog dab tsi?
Glacial acetic acid yog cov dej ntshiab, tseem ceeb tshaj -dawb daim ntawv ntawm acetic acid - feem ntau 99.5% mus rau 99.8% CH3COOH los ntawm qhov hnyav, piv rau 4-8% concentration pom nyob rau hauv tsev neeg vinegar. Nws muaj tus lej CAS64-19-7, thiab qhia txog cov ntaub ntawv hauv qab ob peb lub npe: ethanoic acid, methanecarboxylic acid, lossis qee zaus vinegar acid.
Daim ntawv lo "glacial" piav qhia txog lub cev tiag tiag, tsis yog lus lag luam. Hauv qab li 16.6℃(62℃F), ntshiab acetic acid solidifies rau hauv dej khov -zoo li crystals - yog li lub npe.
Glacial acetic acid vs. vinegaryog ib qho chaw tsis meej pem. Lawv yog tib yam tshuaj lom neeg, tab sis vinegar yog diluted, zaub mov - muaj kev nyab xeeb kev daws teeb meem, thaum glacial acetic acid yog concentrated thiab corrosive, siv nyob rau hauv industrial, tshuaj, thiab chaw kuaj mob es tsis txhob siv ncaj qha.
Vim li cas Acetic Acid raug cais raws li Molecular, Tsis yog Ionic
Qhov txawv los ntawm qhov yuav ua li cas cov atoms tuav ua ke.Ionic compoundsdaim ntawv thaum electrons hloov tag nrho los ntawm ib lub atom mus rau lwm tus - feem ntau yog ib tug hlau muab ib tug electron mus rau ib tug nonmetal - ua ions them uas xauv rau hauv ib tug siv lead ua lattice. Table ntsev (NaCl) yog tus qauv piv txwv.
Molecular compoundsdaim ntawv thaum atoms sib koom electrons es tsis txhob hloov lawv, uas yog dab tsi tshwm sim ntawm nonmetals. Acetic acid tus qauv - ob carbon atoms, plaub hydrogens, ob oxygens, teem ib ncig ntawm ib carboxyl (-COOH) pawg - yog tsim los ntawm hom electron- sib koom, covalent bonding. Tsis muaj hlau nyob hauv cov qauv txhua, thiab tsis muaj ionic lattice tuav nws ua ke. Qhov ntawd yog ib feem loj ntawm vim li cas nws tshwm sim ua kua nyob rau hauv chav tsev kub ntau dua li qhov siab - melting crystalline khoom.
Qhov twg ionic tsis meej pem los ntawm.Acetic acid yog cov kua qaub tsis muaj zog, txhais tau hais tias thaum nws yaj hauv dej, tsuas yog ib feem me me ntawm cov molecules sib cais rau hauv acetate ions (CH3COO⁻) thiab hydrogen ions (H⁺) - tus so nyob twj ywm li nruab nrab molecules. Ntau npaum li cas ionizes nyob ntawm qhov concentration thiab kub: ib qho kev daws teeb meem ionizes proportionally ntau tshaj li ib qho concentrated. Qhov kev sib cais ib nrab no yog vim li cas acetic acid coj zoo li cov kua qaub thiab qhia qee cov cim ionic hauv kev daws - tab sis nws yog ib qho kev daws teeb meem -theem sib npaug, tsis yog pov thawj tias lub compound nws tus kheej yog ionic. Lub compound tsis tshua muaj dissociation tas li (Ka ≈ 1.8 × 10⁻⁵) lees paub qhov no: muaj zog acids thiab muaj tseeb ionic compounds dissociate deb tshaj li ntawd.
Cov kab hauv qab:Nyob rau hauv nws cov ntshiab, undiluted (glacial) lub xeev, acetic acid tshwm sim yuav luag tag nrho raws li tsis muaj zog molecules. Txawm nyob rau hauv dej, nws nyob twj ywm feem ntau molecular - ionized feem yog qhov kev zam, tsis yog txoj cai.
Qhov no Molecular Structure piav qhia txog nws tus cwj pwm
Solubility.Vim hais tias acetic acid yog molecular nrog ib tug polar carboxyl pawg, nws yog tag nrho miscible nrog dej, ethanol, thiab ether - nws sib tov huv si yam tsis xav tau ib tug co- kuab tshuaj los yog surfactant, uas yog ib yam ntawm cov me me polar molecules tab sis tsis yog ionic solids nrog ntau lub qhov rais solubility.
Kev coj ua.Ntshiab glacial acetic acid ua hluav taws xob tsis zoo, vim tsuas yog tsis muaj ntau cov ions dawb tam sim no - feem ntau cov molecules nyob twj ywm. Dissolved hauv dej, qhov me me ionized feem cia nws ua tsis muaj zog, uas yog vim li cas acetic acid yog cais raws li ib tugtsis muaj zog electrolytees tsis yog ib qho muaj zog xws li hydrochloric acid los yog cov ntsev ntsev tag nrho.
Volatility.Molecular compounds feem ntau tuav ua ke los ntawm cov tsis muaj zog intermolecular zog dua li cov ionic, muab cov ntsiab lus qis qis thiab siab dua volatility. Acetic acid haum rau tus qauv ntawd, npaus ib ncig ntawm 117-118℃nrog lub teeb nyem ze ntawm 40℃- hnov ntxhiab ntau dua li cov ionic compound xws li cov ntsev ntsev, uas tsis yaj mus txog 800℃.
Reactivity.Lub ncov qaumteb qabteb, covalent qauv yog functionally vim li cas acetic acid ua hauj lwm zoo raws li ib tug hnyav thiab reagent nyob rau hauv esterification thiab acetylation tshuaj, thiab raws li ib tug precursor rau cov tebchaw xws li vinyl acetate monomer, acetic anhydride, thiab cellulose acetate. Ib qho ionic compound yuav tsis coj ib yam li hauv cov tshuaj tiv thaiv no.
Cov Khoom Siv Lub Cev Siv Lub Sijhawm
| Khoom | Tus nqi |
|---|---|
| CAS Nr | 64-19-7 |
| Molecular Formula | CH3COH (C2H4O2) |
| Molecular Luj | 60.05 g / mol |
| Qhov ntom | ~ 1.049 g / cm³ ntawm 25 degree |
| Melting / Freezing Point | 16.6 ° F (62 ° F) |
| Boiling Point | 117-118 degrees |
| Flash Point | ~ 40℃(104℃F) |
| Ka (acid dissociation tas li) | ~1.8 × 10⁻⁵ |
| Solubility | Tag nrho miscible nrog dej, ethanol, ether |
| Bonding Hom | Covalent (molecular compound) |
Common Purity Qib
Acetic acid feem ntau yog muab rau hauv ob peb tus qauv purity tiers:
| Qib | Hom Purity | Hom kev siv |
|---|---|---|
| Qib Industrial | Ntau dua lossis sib npaug li 99.5% | General chemical synthesis, textiles, industrial processing |
| Glacial / USP-EP Qib | Ntau dua lossis sib npaug li 99.7% | Pharmaceutical, zaub mov- qib kev siv |
| Reagent / ACS Qib | Ntau dua lossis sib npaug li 99.8% | Laboratory thiab analytical siv |
Kev Nyab Xeeb Basics
Glacial acetic acid yog cais raws li corrosive, flammable kua raws li UN 2789, nrog GHS daim ntawv lo yuav tsum tau thov thoob ntiaj teb. It should be stored in tightly sealed, corrosion-resistant containers, kept away from heat sources, and handled with appropriate PPE - gloves, goggles, and adequate ventilation - due to its vapor and skin-contact hazards.
Cov lus nug nquag
Puas yog glacial acetic acid tib yam li acetic acid?
Yog lawm, chemically lawv yog tib lub compound (CH3COOH). "Glacial" yog hais txog cov concentrated, ze li ntawm dej -dawb daim ntawv (99.5%+), as opposed to acetic acid diluted in water at low concentrations.
Puas yog glacial acetic acid soluble hauv dej?
Yog - tag nrho miscible nyob rau hauv ib qho kev faib ua feem, ib tug ncaj qha tshwm sim ntawm nws polar molecular qauv. Kev sib xyaw ua kom pom cov cua sov, yog li dilution yuav tsum tau ua los ntawm kev ntxiv cov kua qaub rau hauv dej maj mam, tsis yog rov qab.
Puas yog glacial acetic acid ua hluav taws xob?
NW nyuam qhuav, nyob rau hauv nws daim ntawv ntshiab. Nws dhau los ua ib qho tsis muaj zog electrolyte ib zaug yaj hauv dej, vim tsuas yog ib feem me me ntawm cov molecules ionize - tsis muaj qhov twg nyob ze ntawm cov conductivity ntawm tag nrho dissociated ionic tov.
Yog vim li cas acetic acid ionize tag nrho yog hais tias nws yog ib tug molecular compound?
Vim nws yog ib tug tsis muaj zog acid - me me, concentration- thiab kub - nyob ntawm ib feem ntawm molecules pub ib tug proton rau dej. Tus cwj pwm sib npaug ntawd tsis hloov qhov sib xyaw ua ke cov qauv kev sib raug zoo; nws yog ib qho kev daws teeb meem - theem cov tshuaj tiv thaiv, tsis yog pov thawj ntawm ionic bonding.
Dab tsi yog qhov txawv ntawm glacial acetic acid thiab vinegar?
Nco ntsoov. Vinegar yog diluted, zaub mov -kev nyab xeeb kev daws teeb meem (kwv yees li 4-8% acetic acid). Glacial acetic acid yog 99.5% + ntshiab, corrosive, thiab npaj rau kev lag luam, tshuaj, los yog kev sim siv es tsis yog siv ncaj qha.
Xaus
Acetic acid yog ib qho tshuaj molecular, tag nrho nres - ib nrab ionization nws pom hauv dej yog qhov tsis muaj zog -acid equilibrium, tsis yog pov thawj ntawm ionic bonding. Qhov tseeb ntawm cov qauv no yog qhov piav qhia txog nws cov dej tsis zoo tag nrho, nws qhov tsis muaj zog (tsis muaj zog) electrolyte tus cwj pwm, nws qhov kub tsis tshua muaj kub, thiab nws cov txiaj ntsig zoo li cov kuab tshuaj thiab cov tshuaj reagent hla cov tshuaj, tshuaj, thiab zaub mov kev lag luam.