Qhov sib txawv tseem ceeb ntawm CFC thiab HCFC yog tias CFC tsuas muaj cov pa roj carbon, fluorine thiab chlorine atoms thaum HCFC muaj hydrogen, carbon, fluorine thiab chlorine atoms. Qhov tseem ceeb tshaj, CFC ua rau ozone depletion loj tab sis HCFC, piv txwv li, muaj qhov cuam tshuam tsawg dua rau cov txheej txheej ozone.
Cov qauv tshuaj ntawm CFC thiab HCFC cuam tshuam rau ib leeg raws li cov tshuaj muaj nyob hauv cov qauv no. Txawm li cas los xij, hais txog cov qauv tshuaj, qhov sib txawv ntawm CFC thiab HCFC yog tias CFC tsis muaj hydrogen atom thaum HCFC muaj hydrogen atom. CFC yog qhov paub zoo tias yog tus pab txhawb rau ozone depletion. Yog li ntawd, nws yog ib qho teeb meem. HCFC yog ib qho kev hloov zoo rau cov khoom phem no.
CFC yog dab tsi?
CFC yog ib chav kawm ntawm cov tebchaw uas muaj tag nrho halogenated paraffin hydrocarbons. Cov tshuaj no tsuas muaj carbon, fluorine thiab chlorine atoms xwb. Cov pa roj carbon atoms nyob rau hauv cov tebchaw tsim covalent bonds nyob rau hauv ib tug tetrahedral symmetry. Cov neeg tsim khoom tsim cov tebchaw no ua cov khoom tsis zoo ntawm methane, ethane thiab propane. Lub npe nrov npe rau chav kawm no yog "Freon". Qhov sib xyaw ua ke ntawm cov chav kawm no feem ntau yog dichlorodifluoromethane. Kev siv ntau ntawm cov tebchaw no yog cov refrigerants, propellants thiab cov kuab tshuaj. Txawm li cas los xij, tom qab kev tshawb fawb pom tau tias cov tshuaj no ua rau ozone depletion. Yog li ntawd, cov tebchaw no tau hloov nrog qee cov tshuaj tsis zoo xws li HCFCs.
Tsis tas li ntawd, lub cev lub cev ntawm cov tebchaw no hloov pauv nrog tus lej thiab hom halogen tam sim no hauv cov khoom sib xyaw. Feem ntau, lawv yog volatile. Tab sis qhov volatility tsawg dua lawv cov niam txiv molecules (alkanes). Qhov tsawg volatility tshwm sim vim lub molecular polarity uas yog induced los ntawm halides; Cov halides no ua rau muaj kev sib cuam tshuam ntawm intermolecular uas ua rau kom nce qhov kub thiab txias, yog li txo qhov volatility. Txawm li cas los xij, vim lawv cov polarity, cov tebchaw no yog cov kuab tshuaj zoo. Tsis tas li ntawd, lawv qhov kub kub ua rau lawv cov tub yees zoo. Ntxiv rau qhov ntawd, cov tebchaw no muaj qhov ntom ntom dua piv rau cov alkanes sib raug.
Daim duab 01: Ozone Depletion
Ntxiv mus, qhov tseem ceeb tshaj plaws cov tshuaj tiv thaiv ntawm CFC yog daim duab tshwm sim ntawm daim ntawv cog lus C-Cl. Peb sau tau raws li nram no.
CCl3F → CCl2F. + Cl.
Cov tshuaj tiv thaiv no tsim cov tshuaj chlorine radical. Nws coj txawv txawv ntawm cov tshuaj chlorine molecule; Cl 2. Thiab qhov radical no nyob ntev ntev hauv cov huab cua sab saud. Nyob rau ntawd, nws catalyzes hloov ntawm ozone mus rau oxygen molecules. Yog li, nws depletes tus nqi ntawm ozone.
HCFC yog dab tsi?
HCFC yog ib chav kawm ntawm cov tshuaj uas muaj cov qauv tshuaj zoo ib yam li CFC. Txawm li cas los xij, tsis zoo li CFC, cov tebchaw no muaj hydrogen atom, ntxiv rau cov pa roj carbon, fluorine thiab chlorine atoms. Raws li ib txwm muaj, cov no yog cov pa roj lossis cov kua evaporative heev. Feem ntau, lawv ruaj khov thiab tsis ua haujlwm.
Cov tshuaj no yog cov khoom siv tau zoo heev rau CFCs. Lawv muaj txiaj ntsig zoo li cov tub yees thiab hauv insulative foams. Txawm li cas los xij, tib neeg tsis siv nws los ua cov kuab tshuaj, thiab nws raug txwv tsis pub siv los ua cov kuab tshuaj hauv ntau lub tebchaws tsim. Qhov tseem ceeb tshaj, cov tshuaj no tsis muaj kev cuam tshuam tam sim ntawd rau ib puag ncig tom qab tso tawm rau ib puag ncig. Vim lawv qhov xwm txheej tsis hloov pauv, lawv tuaj yeem koom nrog cov tshuaj tiv thaiv uas tsim ozone nyob rau theem qis uas tuaj yeem ua rau cov nroj tsuag puas tsuaj. Txij li thaum lawv tsis ruaj khov li CFC thiab yog li tsis tas li nyob rau hauv cov huab cua, cov teebmeem ntawm cov huab cua tsawg heev. Tab sis tseem, cov tebchaw no tuaj yeem xaus rau hauv cov huab cua sab saud ua rau qeeb qeeb ntawm ozone.
Qhov txawv ntawm CFC thiab HCFC yog dab tsi?
CFC yog ib chav kawm ntawm cov tebchaw uas muaj tag nrho halogenated paraffin hydrocarbons. Cov tshuaj no tsuas muaj carbon, fluorine thiab chlorine atoms. Qhov tseem ceeb tshaj, CFC ua rau ozone depletion loj. HCFC yog ib chav kawm ntawm cov tebchaw uas muaj cov qauv tshuaj zoo ib yam li CFC. Tab sis, lawv muaj hydrogen atom, ntxiv rau cov carbon, fluorine thiab chlorine atoms. Txawm li cas los xij, HCFC muaj qhov cuam tshuam tsawg heev rau txheej txheej ozone vim tias nws dhau mus rau photochemical decomposition ua ntej nws mus txog rau saum huab cua. Qhov no yog qhov sib txawv tseem ceeb ntawm CFC thiab HCFC.
Summary – CFC vs HCFC
Ob qho CFC thiab HCFC cov khoom sib txuas yog qhov tseem ceeb ua cov tub yees, tab sis CFCs tsis siv vim lawv qhov cuam tshuam loj rau ib puag ncig. Qhov sib txawv tseem ceeb ntawm CFC thiab HCFC yog tias CFC tsuas muaj cov pa roj carbon, fluorine thiab chlorine atoms thaum HCFC muaj hydrogen atom ntxiv rau carbon, fluorine, thiab chlorine atoms.
