Qhov Tseem Ceeb - Acid-Base Titration vs. Redox Titration
Feem ntau, titrations yog siv los txiav txim siab qhov concentration ntawm cov tshuaj tsis paub (analyte). Feem ntau siv ob txoj kev titrimetric yog acid-base titrations thiab redox titrations. Qhov sib txawv tseem ceeb ntawm acid-base titrations thiab redox titrations yog qhov xwm txheej ntawm cov tshuaj tiv thaiv uas tshwm sim ntawm titrant thiab cov tshuaj ntsuam xyuas hauv titration. Hauv cov kua qaub-puag titrations, cov tshuaj tiv thaiv neutralization tshwm sim thiab hauv redox titrations, cov tshuaj tiv thaiv redox tshwm sim (cov tshuaj tiv thaiv oxidizing thiab txo cov tshuaj tiv thaiv). Kev siv cov ntsuas ntsuas yog feem ntau siv los txiav txim qhov kawg ntawm cov tshuaj tiv thaiv.
Acid-Base Titration yog dab tsi?
Hauv acid-base titrations, ib qho kua qaub (acidic titrations) los yog lub hauv paus (pib titrations) yog siv los ua titrant. Piv txwv ntawm cov kua qaub uas siv hauv acidic titration yog H2SO4, HCl, los yog HNO3. Feem ntau siv cov ntsiab lus titrants yog NaOH, K2CO3 lossis Na2CO3. Acid-base titrations tuaj yeem faib raws li hauv qab no nyob ntawm lub zog ntawm cov kua qaub thiab lub hauv paus.
- Strong acid – muaj zog puag titrations
- Strong acid- qaug zog titrations
- Tsis muaj kua qaub - muaj zog puag titrations
- Weak acid – qaug zog titrations
Nyob rau hauv feem ntau ntawm cov kua qaub-puag titrations, cov ntsuas tau siv los txiav txim qhov kawg ntawm cov tshuaj tiv thaiv. Cov ntsuas sib txawv yog siv nyob ntawm seb hom titration raws li tau hais los saum toj no.
Dab tsi yog Redox Titration?
Ib redox titration cuam tshuam nrog cov tshuaj tiv thaiv redox. Cov tshuaj tiv thaiv Redox muaj ob qhov kev tshwm sim; oxidation cov tshuaj tiv thaiv thiab txo cov tshuaj tiv thaiv. Ob qho tib si oxidation thiab txo cov txheej txheem tshwm sim nyob rau tib lub sijhawm uas tso cai rau peb txiav txim siab ua tiav cov tshuaj tiv thaiv. Qhov no tseem hu ua qhov kawg ntawm qhov titration. Qhov no tuaj yeem txiav txim siab ntau txoj hauv kev; siv qhov taw qhia electrodes, cov ntsuas redox (qhov taw qhia ua kom muaj xim sib txawv ntawm oxidation-txo lub xeev), thiab cov ntsuas tsis-redox (qhov taw qhia ua rau xim thaum muaj ntau tshaj ntawm titrant ntxiv).
Qhov txawv ntawm Acid-Base Titration thiab Redox Titration yog dab tsi?
Nature of the reaction:
Acid-Base Titration: Cov kua qaub-puag titration cuam tshuam nrog cov tshuaj tiv thaiv nruab nrab ntawm cov tshuaj ntsuam xyuas (cov tshuaj uas tsis paub meej) thiab cov kua qaub lossis cov titrant yooj yim.
Redox Titration: Cov tshuaj tiv thaiv redox cuam tshuam nrog oxidation thiab txo cov tshuaj tiv thaiv ntawm cov tshuaj ntsuam xyuas thiab cov titrant. Tsis muaj txoj cai zoo li no uas tivthaiv oxidizes thiab qhov twg txo. Ob qho tshuaj ntsuam xyuas los yog cov titrant oxidizes, thiab cov khoom seem txo qis raws li.
Kev txiav txim siab ntawm qhov kawg:
Acid-Base Titration: Feem ntau, pH ntsuas, pH ntsuas lossis ntsuas ntsuas ntsuas yog siv los txiav txim qhov kawg ntawm cov kua qaub-piv titration.
Redox Titration: Feem ntau siv txoj hauv kev los txiav txim qhov kawg ntawm cov tshuaj tiv thaiv redox yog siv lub potentiometer lossis qhov ntsuas redox. Tab sis, feem ntau yog cov tshuaj ntsuam xyuas los yog cov titrant tsim cov xim ntawm qhov kawg. Yog li ntawd, tsis tas yuav muaj qhov ntsuas ntxiv hauv cov xwm txheej ntawd.
Examples:
Acid-Base Titration:
| Type | Reaction (Indicator) |
| Strong acid – muaj zog puag titration | HCl + NaOHàNaCl + H2O (Phenolphthalein / Methyl txiv kab ntxwv) |
| Strong acid – qaug zog titration | HCl + NH3à NH3Cl (Methyl txiv kab ntxwv) |
| Tsis muaj kua qaub - muaj zog puag titration | CH3COOH + NaOHà CH3COONa + H2O (Phenolphthalein) |
| Tsis muaj kua qaub – tsis muaj zog titration | CH3COOH + NH3àCH3COO- +NH4+(Tsis haum ntsuas) |
Redox Titration:
2 KMnO4 + 5 H2C2O4 + 6 HCl → 2 MnCl2 + 2KCl + 10 CO2 + 8 H2 O
(+7)(+3)(+2)(+4)
Hauv cov tshuaj tiv thaiv saum toj no, permanganate txo qis thaum oxalic acid yog oxidized. Thaum cov tshuaj tiv thaiv tiav, cov xim liab ntawm permanganate hloov mus rau hauv cov xim tsis muaj xim.
KMnO4 + 5FeCl2 +8HCl → 5FeCl3+MnCl 2+KCl+4H2O
(+7)(+2)(+3)(+2)
