Tikanga Tātari Rōrahi
He tikanga nui te tātari rōrahi i roto i te matū tātari, e whakamahia ana hei whakatau i te kukū o tētahi matū mā te ine i te rōrahi o te otinga tauhohe e hiahiatia ana hei tae atu ki te pūwāhi ōrite. He whānuitia ngā whakamahinga o tēnei tikanga, mai i te whakamātautau kounga wai me te tātari kai ki ngā taumata matū hohe i roto i ngā rongoā, ki te whakahaere kounga ahumahi. Nā te mea e whakawhirinaki ana ki ngā ine rōrahi ngāwari noa iho, he tikanga whai hua, he ohanga, he tika hoki te tātari rōrahi ina tika te whakahaere.
Whakamāramatanga me ngā Mātāpono Taketake
Ko te tātari rōrahi (titrimetry) he tikanga tauanga e ine ana i te rōrahi o tētahi otinga paerewa (titrant) e tauhohe ana i runga i te stoichiometric me te matū e tātarihia ana (analyte). Ka haere tonu te tauhohenga i waenga i te titrant me te analyte kia tae rā anō ki tētahi āhuatanga ōrite, arā, ina rite tonu te maha o ngā mole o te titrant e tauhohe ana ki te maha o ngā mole o te analyte e ai ki te whārite tauhohenga.
Ko ngā mātāpono matua o te volumetrics ko:
1. Me tino motuhake te tauhohenga, ā, me tino tika (me tata tino tika rānei).
2. Me mārama te stoichiometry o te tauhohenga kia taea ai te whakahaere i ngā tataunga kukū.
3. Me whakatau tika te pūwāhi mutunga o te ine ira, mā te whakamahi i tētahi tohu, i tētahi taputapu ine rānei (hei tauira, te mita pH).
4. Me mōhiotia tika te kukū o te otinga paerewa, kia taea ai te huri i te rōrahi e whakamahia ana hei nui o te matū.
Ngā Wāhanga Hira i roto i te Tātaritanga Rōrahi
Hei whakaputa raraunga tika mā te tātaritanga rōrahi, me whai whakaaro ki ngā wāhanga e whai ake nei:
1. Otinga Paerewa (Titran)
Ko te otinga paerewa he otinga e mōhiotia ana te kukū. E rua ngā momo:
– Ngā paerewa matua, arā, ngā matū parakore he pumau te hanganga, ā, ka taea te pauna tika hei hanga otinga me ngā kukū tika (hei tauira, Na2CO3, K2Cr2O7, ētahi waikawa oxalic).
– Te paerewa tuarua, arā, he otinga e whakatauhia ana tōna kukū mā te whakataurite ki tētahi paerewa tuatahi (hei tauira, HCl, NaOH, KMnO4 i raro i ētahi tikanga).
2. Tātari
He matū te analyte e whakatauhia ana tōna kukū. Ka taea te waiho hei waikawa, hei turanga, hei katote konganuku, hei kaiwhakahāora, hei whakaiti rānei, hei aha atu rānei, mena ka tauhohe ki te titrant i roto i te huarahi e taea ai te ine.
3. Ngā Tohu me ngā Tikanga Whakatau i te Pūwāhi Mutunga
Ko te pūwāhi mutunga ko te tohu kua mutu te ine ine. Ko tētahi huarahi noa hei whakatau ko:
– Ngā tohu tae, pērā i te phenolphthalein, te methyl orange, te methyl whero.
– Te Pūtake Hiko, te aroturuki i ngā panonitanga o te pūmanawa hiko, te pH rānei.
– Te ine i te kawe hiko, te ine i ngā panoni o te kawe hiko.
– Te ine i te turbidimetry/te pito mutunga o te ua, e aroturuki ana i te hanganga o te paru.
He mea tino nui te whiriwhiri i te tohu nā te mea me tata te huringa tae o te tohu ki te pūwāhi ōrite.
4. Taputapu Rōrahi
Ko ngā oko karaihe e whakamahia whānuitia ana ko:
– Pūrere, hei maturuturu i te titrant me te tino tika.
– He pipeti rōrahi, hei tango i te rōrahi tika o te analyte.
– He pounamu ine, hei whakarite i ngā otinga paerewa i tētahi rōrahi kua whakaritea.
– Erlenmeyer, hei ipu tauhohenga titration.
Ko te tika o te pānui i te meniscus, te ma o ngā taputapu, me te tikanga ine ine (hei tauira, te heke mārire ki te pito whakamutunga) ngā mea nui e whakatau ana i te kounga o ngā hua.
Ngā Momo Tātaritanga Rōrahi
Ka taea te whakarōpū i te tātari rōrahi i runga i te momo tauhohenga e puta ana.
1. Te Whakatōpūtanga Waikawa-Pūtake
Ko te ine i te waikawa-pūtake te mea tino noa. Ko te kaupapa matua e hangai ana ki te tauhohenga whakakore i waenga i te waikawa me te pūtake. Ngā tauira whakamahinga:
– Whakatauhia te nui o te HCl mā te whakamahi i te titrant NaOH.
– Whakatauhia te taumata o te waikawa acetic i roto i te winika.
– Te ine i te kawakore o te wai.
Me mārama ki te kaha o te waikawa/turanga (kaha, ngoikore rānei) mō tēnei titration nā te mea ka pā ki te pihi titration me te kōwhiringa tohu. Hei tauira, he pai te Phenolphthalein mō ngā titration waikawa ngoikore–turanga kaha, ko te methyl orange ia e whakamahia ana mō ngā titration waikawa kaha–turanga ngoikore, i runga i ngā āhuatanga.
2. Te Whakatitoretanga Redox (Te Whakaiti-Waikura)
Ko ngā titrating redox e pā ana ki te whakawhiti irahiko. Ka mahi te titrant hei ākena whakahāngai, hei ākena whakaiti rānei. Ko ngā tauira noa ko:
– Ka whakamahia e te Permanganometry te KMnO4 hei matū whakapūkara kaha. E whakamahia ana hoki te KMnO4 hei tohu nā tōna tae.
– Ka whakamahia e te iodometry/iodimetry te iodine, te thiosulfate rānei hei whakatau i ngā taumata o ngā kaiwhakahāora, ngā kaiwhakaiti rānei.
– Te whakamāoritanga ira-rua mā te whakamahi i te K2Cr2O7 hei whakahāora.
E whakamahia whānuitia ana te titration redox hei tātari i ngā taumata o ngā matū pēnei i te Fe(II), te huaora C, te chlorine kore utu, tae atu ki te ihirangi o ngā rauemi waikura ahumahi.
3. Te Ine i te Ua
Ka puta te titration precipitation ina tauhohe te titrant ki te analyte hei hanga i tētahi matū kore e tino wairewa. Ko tētahi tauira matarohia ko te titration argentometric, mā te whakamahi i te AgNO3 hei whakatau i ngā halide (Cl⁻, Br⁻, I⁻). He rerekētanga te tikanga argentometric:
– Mohr, mā te whakamahi i te tohu kōromate.
– Volhard, mā te whakamahi i te titration whakamuri me te thiocyanate.
– Ngā Fajans, mā te whakamahi i ngā tohu mimiti.
He mea whai hua tēnei momo ira-whakapūtātanga mō te whakatau i te nui o te tote (hei tauira, te pūhaumāota i roto i te wai) me te tātari i ētahi anion.
4. Te Ine Whakapūmau Matatini
Ko te titration complexometric e pā ana ki te hanganga o tētahi matatini pumau i waenga i tētahi katote konganuku me tētahi ligand. Ko te matū tino rongonui ko te EDTA (Ethylenediaminetetraacetic acid). Ka whakamahia tēnei tikanga hei:
– Te whakatau i te mārō o te wai (Ca²⁺ me Mg²⁺).
– Te tātaritanga o ngā konganuku i roto i ngā otinga ahumahi.
– Te whakatau i ngā katote konganuku i roto i ngā tauira taiao.
Ka āwhina ngā tohu matatini (hei tauira, te Eriochrome Black T) ki te whakaatu i ngā huringa ina herea katoatia te EDTA ki te katote konganuku.
Ngā Wāhanga Whānui o te Tukanga Titration
Ahakoa he rerekē ngā taipitopito o ia momo ira tātai, ko te rerenga whānui o te tātari rōrahi ko:
1. Te whakarite i te otinga paerewa (te whakapūmau rānei i te titrant mēnā e tika ana).
2. Te tango tauira tika o ngā tātaritanga mā te whakamahi i tētahi pipette rōrahi.
3. Te tāpiri i ngā tohu, te tāuta rānei i ngā taputapu ine (ngā mita pH).
4. Te Whakatātaitanga: ka maturuturuhia te whakatātaitanga mai i te pūrere me te whakaohooho kia tae rā anō ki te pūwāhi mutunga.
5. Te tirotiro i te mutunga: ka eke te huringa tae pumau, te uara taputapu ine rānei ki tētahi āhua.
6. Tuhia te rōrahi o te titrant i whakamahia, ka tatau i te kukū o te analyte i runga i te stoichiometry.
Me whakamahi anō i ngā inenga (kia rua, kia toru rānei ngā wā) kia taea ai te tāruarua, ā, he paku rerekē noa ngā hua.
Ngā Tātaitanga i roto i te Tātaritanga Rōrahi
Ko ngā tātaitanga o te kukū o te analyte e whakamahi ana i ngā ariā o ngā mole me te stoichiometry. He māmā noa iho, ko te maha o ngā mole o te titrant e tauhohe ana ko:
\[
n = M \whakanuia V
\]
me te \(n\) = ngā ira, \(M\) = te mōroiti, \(V\) = te rōrahi (L). Muri iho, ka whakatauhia ngā ira o te analyte mai i te ōwehenga o ngā taunga tauhohenga. Mai i ngā ira o te analyte, ka taea te tatau i te kukū, te papatipu, te ōrau rānei o te tauira.
Ngā Painga me ngā Here
Keunggulan
– He tere, he iti hoki te utu ina whakaritea ki ngā taputapu matatau.
– He tino teitei te tika mēnā he pai te paerewa o te ine taumata.
– He māmā noa te tukanga, ā, ka taea te whakamahi ki ngā momo tauira rerekē.
– He pai mō te tātari auau i roto i te whakahaere kounga.
Ngā Here
– Me mārama te tauhohenga, me te pūwāhi whakamutunga e ngāwari ana te kite.
– Ka uaua pea te whakamahi i te tohu nā te mea he kapua ētahi tauira.
– Ka pāngia ngā hua e ngā hapa iti i te pānui o te pūwero, te whakatau rānei i te pūwāhi.
– Kāore i te pai i ngā wā katoa mō ngā kukū iti rawa o ngā tātaritanga me te kore he tikanga tāpiri.
Te Katinga
He tūāpapa nui ngā tikanga tātari rōrahi i roto i te matū tātari nā te mea ka whakakotahi i ngā mātāpono stoichiometric me ngā ine rōrahi tika. Mā te whakamahi i ngā momo tikanga titration—waikawa-pūtake, redox, precipitation, me te complexometry—ka taea e te tātari rōrahi te whakatutuki i ngā hiahia tātari o ngā taiwhanga mātauranga me ngā taiwhanga ahumahi. Ko te kī ki te angitu kei roto i te whiriwhiri i te tauhohenga tika, te whakarite i te otinga, te whakamahi marie i ngā taputapu rōrahi, me te whakatau tika i te mutunga. Mā te whakamahi tika i ngā tikanga, ka noho tonu te tātari rōrahi hei tikanga pono mō te whakatau i te kukū o ngā matū i roto i te whānuitanga o ngā tono.
