Qhov sib txawv tseem ceeb ntawm thymolphthalein thiab phenolphthalein yog qhov kev hloov xim ntawm thymolphthalein tshwm sim los ntawm tsis muaj xim mus rau xiav, qhov kev hloov xim ntawm phenolphthalein tshwm sim los ntawm tsis muaj xim mus rau xim liab thaum hloov cov tshuaj tiv thaiv los ntawm acidic mus rau hauv paus.
Thymolphthalein thiab phenolphthalein yog ob qhov ntsuas pH sib txawv uas muaj txiaj ntsig zoo hauv cov txheej txheem titrimetric analytical.
YThymolphthalein yog dab tsi?
Thymolphthalein yog ib hom phthalein dye uas muaj txiaj ntsig zoo li cov kua qaub-puag qhia. Cov tshuaj formula ntawm thymolphthalein yog C28H30O4. Nws yog qhov ntsuas pH uas muab nws cov xim hloov thaum hloov pH ntawm cov tshuaj tiv thaiv sib tov. Kev hloov pauv pH ntawm qhov ntsuas no yog nyob ib puag ncig 9.3 - 10.5. Thymolphthalein tsis muaj xim hauv qab pH 9.3, thaum nws tshwm xim xiav ntawm pH qhov tseem ceeb tshaj 10.5. Ntxiv mus, lub molar extinction coefficient ntawm thymolphthalein yog 38 000 M-1cm-1 ntawm 595 nm rau cov xim xiav xim anion.
Daim duab 01: Cov Qauv Tshuaj ntawm Thymolphthalein Qhov Ntsuas
Qhov kev sib txuas ntawm thymolphthalein tuaj yeem ua tau siv thymol thiab phthalic anhydride. Cov khoom ntawm no cov tshuaj tiv thaiv synthesis yog cov hmoov dawb uas kuj yog cov khoom lag luam muaj nyob hauv daim ntawv ntawm thymolphthalein. Nyob rau hauv high kub, cov khoom no nyiam decompose. Tsis tas li ntawd, cov tshuaj no yog siv los ua laxative thiab kom ploj mus ib yam nkaus.
Phenolphthalein yog dab tsi?
Phenolphthalein yog pH qhov taw qhia uas muaj txiaj ntsig zoo li cov kua qaub-base titration indicator. Qhov no yog qhov qhia tau ntau heev uas peb feem ntau siv hauv peb cov txheej txheem titration. Cov tshuaj formula ntawm cov tshuaj no yog C20H14O4. Peb tuaj yeem sau lo lus no yooj yim li "Hin" lossis "phph". Cov xim acidic ntawm phenolphthalein yog xim tsis muaj xim, thaum xim xim ntawm phenolphthalein yog xim liab. Qhov pH ntau rau qhov kev hloov xim no tshwm sim yog nyob ib puag ncig 8.3 - 10.0 pH.
Ntxiv mus, qhov ntsuas phenolphthalein yog me ntsis dej-soluble, thiab feem ntau, nws yaj hauv cawv. Ua li no, peb tuaj yeem siv lawv yooj yim hauv titrations. Phenolphthalein yog ib qho tsis muaj zog acid uas tuaj yeem tso cov protons rau cov tshuaj. Lub acidic daim ntawv ntawm phenolphthalein yog nonionic, thiab nws yog xim tsis muaj xim. Daim ntawv deprotonated ntawm phenolphthalein yog xim liab, thiab nws yog ib daim ntawv ionic. Yog hais tias peb ntxiv ib lub hauv paus rau cov tshuaj tiv thaiv sib tov uas muaj phenolphthalein qhia, qhov sib npaug ntawm cov ionic thiab nonionic cov ntaub ntawv nyhav hloov mus rau lub xeev deprotonated vim hais tias cov protons raug tshem tawm los ntawm cov tshuaj.
Daim duab 02: Xim Xim ntawm Phenolphthalein
Hais txog kev sib txuas ntawm phenolphthalein qhia, peb tuaj yeem tsim nws los ntawm kev sib xyaw ntawm phthalic anhydride nyob rau hauv lub xub ntiag ntawm ob qhov sib npaug ntawm phenol nyob rau hauv acidic tej yam kev mob. Ntxiv mus, cov tshuaj tiv thaiv no tuaj yeem ua rau muaj kev sib xyaw ntawm zinc chloride thiab thionyl chloride.
Qhov txawv ntawm Thymolphthalein thiab Phenolphthalein yog dab tsi?
Thymolphthalein thiab phenolphthalein yog ob qhov ntsuas pH sib txawv uas muaj txiaj ntsig zoo hauv cov txheej txheem tshuaj ntsuam titrimetric. Qhov sib txawv tseem ceeb ntawm thymolphthalein thiab phenolphthalein yog qhov kev hloov xim ntawm thymolphthalein tshwm sim los ntawm tsis muaj xim mus rau xiav, thaum cov xim hloov ntawm phenolphthalein tshwm sim los ntawm tsis muaj xim mus rau xim liab thaum hloov cov tshuaj tiv thaiv los ntawm acidic mus rau hauv paus. Ntxiv mus, lub active pH ntau ntawm thymolphthalein yog 9.3 mus rau 10.5 whereas lub nquag pH ntau ntawm phenolphthalein yog 8.3 mus rau 10.0.
Cov hauv qab no qhia txog qhov sib txawv ntawm thymolphthalein thiab phenolphthalein hauv daim ntawv teev npe rau ib sab ntawm kev sib piv.
Summary – Thymolphthalein vs Phenolphthalein
Thymolphthalein thiab phenolphthalein yog ob qhov ntsuas pH sib txawv uas muaj txiaj ntsig zoo hauv cov txheej txheem tshuaj ntsuam titrimetric. Qhov sib txawv tseem ceeb ntawm thymolphthalein thiab phenolphthalein yog qhov kev hloov xim ntawm thymolphthalein tshwm sim los ntawm tsis muaj xim mus rau xiav, qhov kev hloov xim ntawm phenolphthalein tshwm sim los ntawm tsis muaj xim mus rau xim liab thaum hloov cov tshuaj tiv thaiv los ntawm acidic mus rau hauv paus.
