Qhov Tseem Ceeb - Ethanol vs Ethanoic Acid
Txawm hais tias Ethanol thiab Ethanoic acid muaj cov npe zoo sib xws, qhov sib txawv tseem ceeb tuaj yeem pom ntawm lawv vim tias lawv yog ob qhov sib txawv ntawm cov organic sib xyaw uas muaj ob pawg ua haujlwm sib txawv. Ethanol yog tus thib ob yooj yim tshaj plaws ntawm tsev neeg cawv thaum ethanoic acid yog tus thib ob yooj yim tus tswv cuab ntawm pawg carboxylic acid. Lawv ob leeg tsuas muaj ob lub Carbon atoms ntxiv rau cov pab pawg ua haujlwm tam sim no hauv cov molecule. Thaum peb sib piv lawv cov khoom siv tshuaj lom neeg; ob qho tib si yog siv los ua cov kuab tshuaj organic thiab muaj cov yam ntxwv tsw. Hauv kev sib piv, ethanoic acid yog acidic dua li ethanol.
Ethanol yog dab tsi?
Lub npe ntawm ethanol yog ethyl cawv. Nws pab pawg ua haujlwm yog pawg hydroxyl (-OH pawg). Tag nrho cov khoom siv tshuaj xws li reactivity, acidity los yog hauv paus yog nyob ntawm cov pab pawg ua haujlwm. Ethanol muaj ntxhiab tsw heev, thiab nws yog ib qho tsis haum tshuaj. Ethanol tseem ceeb heev hauv nws cov ntawv thov kev lag luam; nws yog cov kuab tshuaj muaj kev nyab xeeb, siv roj, siv los tsim tshuaj thiab tshuaj pleev ib ce thiab nws yog cov khoom tseem ceeb hauv cov dej cawv. Ethanol tuaj yeem tsim tawm hauv tsev siv cov khoom pov tseg xws li pob kws, qab zib, lossis nyom.
YEthanoic acid yog dab tsi?
Lub npe siv feem ntau rau Ethanoic acid yog acetic acid. Nws yog cov kua uas tsis muaj xim nrog cov yam ntxwv qaub saj thiab pungent tsw. Nws muaj cov qauv molecular ntawm CH3COOH. Lub undiluted daim ntawv ntawm ethanoic acid yog hu ua "glacial acetic acid" thiab kwv yees li 3-9% ntawm cov kua qaub los ntawm ntim yog siv los ua vinegar. Ethanoic acid yog suav tias yog cov kua qaub tsis muaj zog; tab sis, nws yog corrosive thiab tuaj yeem tawm tsam ntawm daim tawv nqaij.
Qhov txawv ntawm Ethanol thiab Ethanoic acid yog dab tsi?
yam ntxwv ntawm Ethanol thiab Ethanoic acid:
Functional Group:
Ethanol: Hydroxyl pawg (-OH pawg) yog pawg ua haujlwm hauv ethanol. Nws yog cov yam ntxwv ntawm cawv. Tag nrho cov cawv muaj tsawg kawg yog ib pawg -OH hauv lawv cov qauv.
Ethanoic acid: Cov pab pawg ua haujlwm hauv ethanoic acid yog ib pawg -COOH. Nws yog ib txwm muaj rau tag nrho cov carboxylic acids.
Properties:
Ethanol: Ethanol yog ib qho dej cawv monohydric nrog cov ntxhiab tsw qab uas kub ntawm 78.5 ° C. Nws tsuas yog hydrocarbon uas yaj hauv dej hauv txhua qhov sib npaug. Ethanol reacts nrog alkaline KMnO4 muab ethanoic acid thaum ethanoic acid tsis hnov mob nrog alkaline KMnO4.
Ethanoic acid: Nws yog ib qho tsis muaj zog monoprotic acid hauv cov kua dej (pKa=4.76). Cov kua acetic acid yog cov kuab tshuaj zoo li dej. Nws dissolves ob qho tib si polar kua xws li qab zib thiab ntsev, thiab cov kua tsis-polar xws li roj thiab cov khoom xws li sulfur thiab iodine. Nws yog yooj yim thiab tag nrho miscible nrog dej chloroform, thiab hexane. Acetic acid muaj cov ntxhiab tsw ntxhiab tsw.
Siv:
Ethanol: Ethanol muaj nyob rau hauv cov dej cawv thiab kuj siv los ua biofuel rau tsheb. Nws yog cov kuab tshuaj zoo uas tuaj yeem yaj ntau cov organic daws teeb meem uas yog insoluble hauv dej. Ethanol yog siv los tsim ntau cov tshuaj tsw qab, tshuaj pleev ib ce, thiab cov kua roj vanish hauv kev lag luam xim.
Ethanol li roj:
CH3CH2OH + 3O2 → 2CO 2 + 3H2O
Ethanoic acid: Acetic acid yog siv los ua tshuaj reagent los tsim lwm yam tshuaj. Nws yog siv ntau dua los tsim cov yas acetate monomer; vinyl acetate tuaj yeem ua polymerized los tsim polyvinyl chloride lossis lwm yam polymers. Tsis tas li ntawd, acetic acid yog siv los tsim cov esters uas yog siv rau hauv inks, paintings thiab coatings. Acetic anhydride yog lwm cov tshuaj tseem ceeb uas tuaj yeem ua ke los ntawm kev sib xyaw ob lub molecules ntawm acetic acid. Ib qho me me ntawm ethanoic acid yog siv los tsim cov kua qaub hauv tsev.
Acidity:
Ethanol: Ethanol tsis ua rau Sodium bicarbonate (NaHCO₃) lossis hloov xim ntawm daim ntawv xiav litmus. Yog li ntawd, nws yog acidic tsawg dua ethanoic acid.
Ethanoic acid: Ethanoic acid yog cov kua qaub tsis muaj zog uas cuam tshuam nrog Sodium bicarbonate (NaHCO₃) tso CO2 roj. Tsis tas li ntawd, nws hloov xiav litmus rau hauv liab.
Image Courtesy: "Ethanol-3D-pob". (Public Domain) ntawm Wikimedia Commons "Acetic acid dimer 3D pob" los ntawm Jynto (tham) - Tus kheej ua haujlwm.(CC0) ntawm Wikimedia Commons
