Dab tsi yog cawv nrog piv txwv?
Cawv yog ib chav kawm ntawm cov organic tebchaw uas muaj cov pab pawg ua haujlwm hydroxyl (-OH). Lawv tuaj yeem raug faib ua thawj, theem nrab, lossis qib thib ob raws li cov lej ntawm alkyl pawg sib raug zoo rau cov pa roj carbon atom uas coj cov pawg hydroxyl. Cawv ua lub luag haujlwm tseem ceeb hauv ntau yam kev lag luam, cov txheej txheem lom neeg, thiab lub neej txhua hnub. Hauv tsab xov xwm no, peb yuav tshawb txog ntau hom cawv, lawv cov khoom, thiab cov piv txwv ntawm txhua tus.
Kev faib dej cawv
Cawv tuaj yeem raug cais raws li hom carbon atom txuas rau pawg hydroxyl. Cia peb saib peb yam tseem ceeb:
1. Thawj Cwj Pwm: Hauv thawj cov cawv, cov pa roj carbon atom bearing pawg hydroxyl txuas nrog tsuas yog ib pawg alkyl. Cov mis mos rau thawj cov cawv yog RCH2OH, qhov twg R sawv cev rau pawg alkyl. Ib qho piv txwv ntawm thawj cawv yog ethanol (C2H5OH), uas feem ntau pom muaj nyob rau hauv cov dej cawv. Ethanol kuj tseem siv los ua cov kuab tshuaj thiab roj.
2. Secondary Alcohols: Secondary alcohols muaj pawg hydroxyl txuas nrog cov pa roj carbon atom, uas yog sib txuas rau ob pawg alkyl. Cov mis rau cov cawv thib ob yog RR'CHOH, qhov twg R thiab R' sawv cev rau pawg alkyl. Isopropyl cawv (C3H7OH) yog ib qho piv txwv ntawm cov cawv thib ob. Nws yog siv los ua tshuaj tua kab mob, hnyav, thiab tshuaj tua kab mob.
3. Tertiary Alcohols: Tertiary alcohols muaj pawg hydroxyl txuas nrog cov pa roj carbon atom, uas yog sib txuas rau peb pawg alkyl. Cov mis mis rau cov dej cawv tertiary yog RR'R"COH, qhov twg R, R', thiab R" sawv cev rau pawg alkyl. Ib qho piv txwv ntawm tertiary cawv yog tert-butyl cawv (C4H10O). Nws yog siv los ua ib qho hnyav thiab denaturant.
Lub cev thiab tshuaj muaj zog ntawm Cawv
Cawv muaj qhov tshwj xeeb ntawm lub cev thiab tshuaj lom neeg vim muaj cov pab pawg hydroxyl. Cia peb tham txog qee yam ntawm lawv cov khoom tseem ceeb:
1. Solubility: Cawv nrog txog li peb carbon atoms yog soluble hauv dej vim pawg hydroxyl muaj peev xwm tsim hydrogen bonds nrog dej molecules. Piv txwv li, ethanol, nrog nws pawg hydroxyl, yog miscible nrog dej nyob rau hauv tag nrho cov proportions. Txawm li cas los xij, raws li cov kab txuas carbon ntev nce, cov solubility hauv dej txo.
2. Boiling Point: Cawv feem ntau muaj cov ntsiab lus kub siab dua piv rau hydrocarbons ntawm qhov hnyav molecular. Qhov no yog vim muaj kev sib txuas ntawm cov hydrogen sib txuas ntawm cov cawv molecules, ua rau lawv cov ntsiab lus kub. Piv txwv li, ethanol muaj qhov kub ntawm 78.37 degree, thaum ethane, hydrocarbon nrog ib qho hnyav molecular, boils ntawm -88.63 degree .
3. Reactivity: Cawv tuaj yeem raug ntau yam tshuaj lom neeg vim muaj cov pab pawg hydroxyl. Qee cov tshuaj tiv thaiv muaj xws li oxidation, lub cev qhuav dej, esterification, thiab kev hloov pauv. Cov tshuaj tiv thaiv no ua rau cov cawv ntau yam sib xyaw ua ke, dav siv hauv kev lag luam xws li tshuaj, tshuaj pleev ib ce, thiab cov organic synthesis.
Piv txwv ntawm Cawv thiab Lawv Daim Ntawv Thov
Tam sim no cia peb tshawb txog qee qhov piv txwv tshwj xeeb ntawm cawv thiab lawv cov ntawv thov hauv ntau qhov chaw:
1. Methanol (CH3OH): Methanol yog cov cawv uas yooj yim tshaj plaws, tsim los ntawm ib pawg methyl sib txuas rau hydroxyl pawg. Nws feem ntau yog siv los ua cov kuab tshuaj, tshuaj tiv thaiv kab mob, thiab roj hauv cov tsheb sib tw. Methanol kuj yog ib qho tseem ceeb raw khoom nyob rau hauv zus tau tej cov formaldehyde thiab acetic acid.
2. Propanol (C3H8O): Propanol yog thawj cov cawv uas muaj peb-carbon saw. Nws yog feem ntau siv los ua cov kuab tshuaj hauv kev lag luam tshuaj thiab tshuaj pleev ib ce. Propanol kuj muaj cov tshuaj tua kab mob thiab siv rau hauv cov tshuaj ntxuav tes thiab tshuaj tua kab mob.
3. Butanol (C4H10O): Butanol yog plaub-carbon cawv uas muaj nyob rau hauv plaub hom isomeric: n-butanol, isobutanol, sec-butanol, thiab tert-butanol. Cov isomers no muaj ntau daim ntawv thov, suav nrog kev siv cov kuab tshuaj, roj additives, thiab cov khoom siv raw hauv kev sib xyaw ntawm cov tshuaj xws li plastics thiab hluavtaws roj hmab.
4. Glycerol (C3H8O3): Glycerol, tseem hu ua glycerin, yog triol cawv nrog peb pawg hydroxyl. Nws yog cov kua uas tsis muaj xim thiab tsis muaj ntxhiab uas siv dav hauv kev lag luam tshuaj, tshuaj pleev ib ce, thiab khoom noj khoom haus. Glycerol yog cov khoom tseem ceeb hauv kev tsim cov xab npum, moisturizers, thiab sweeteners.
5. Phenol (C6H6O): Phenol yog ib qho tshuaj lom thiab corrosive compound muaj nyob rau hauv ntau yam tshuaj siv. Nws yog muab los ntawm benzene thiab feem ntau siv los ua tshuaj tua kab mob, tshuaj tua kab mob, thiab ua ntej hauv kev tsim cov yas, dyes, thiab tshuaj.
Xaus
Cawv yog ntau yam organic tebchaw nrog ntau yam kev siv thiab cov khoom. Lawv tau muab faib ua thawj, theem nrab, thiab qib qib dej cawv raws li cov qauv ntawm cov pa roj carbon atom txuas rau pawg hydroxyl. Cawv muaj cov yam ntxwv tshwj xeeb xws li solubility, boiling point, thiab reactivity vim muaj cov pab pawg hydroxyl. Kev nkag siab txog ntau hom cawv thiab lawv cov ntawv thov yog qhov tseem ceeb hauv ntau yam kev lag luam thiab lub neej txhua hnub. Txawm hais tias nws yog ethanol hauv koj cov dej haus uas koj nyiam lossis isopropyl cawv siv los tua cov kab mob, cawv ua lub luag haujlwm tseem ceeb hauv peb lub ntiaj teb.