Titration ea Asiti-Base ke eng?
Titration ea motheo oa asiti ke mokhoa oa tlhahlobo ea lik'hemik'hale o sebelisoang khafetsa lilaboratoring ho fumana hore na tharollo ea asiti kapa ea motheo e na le bokae. Mokhoa ona o bonolo ka khopolo-taba, empa o bohlokoa haholo ts'ebetsong, haholo-holo thutong, indastering, meriana, lijong le tikolohong. Titration e re lumella ho fumana hore na ntho e na le bokae ka har'a tharollo ntle le ho e lekanya ka kotloloho, empa ho e-na le hoo ka karabelo e ka lekanngoang ea ho se nke lehlakore.
Ho utloisisa Titration ea Acid-Base
Ka kakaretso, titration ke mokhoa oa tlhahlobo ea volumetric, o itšetlehileng ka ho lekanya bophahamo. Ho titration ea acid-base, karabelo e hlahang ke karabelo ea neutralization: asiti e arabela le motheo ho hlahisa letsoai le metsi. Litekong, tharollo e nang le mahloriso a tsejoang e bitsoa titrant (hangata e behoa ka hare ho burette), ha tharollo eo mahloriso a eona a lokelang ho fumanoa e bitsoa analyte (hangata e behoa ka har'a flask ea Erlenmeyer).
Sepheo sa mantlha sa titration ea acid-base ke ho fumana ntlha ea equivalence, ntlha eo palo ea li-mole tsa acid e arabelang ho eona e lekanang ka mokhoa o sa fetoheng le palo ea li-mole tsa base tse arabelang. Hobane ntlha ea equivalence ha se kamehla e bonahalang habonolo, sesupo kapa sesebelisoa sa ho lekanya se kang pH meter se sebelisoa ho lemoha ha karabelo e fihlile ntlheng ena.
Melao-motheo ea Motheo ea Likarabelo tsa ho se nke lehlakore
Karabelo e bonolo ka ho fetisisa ea ho se nke lehlakore e ka hlalosoa ka tsela e latelang:
– Asiti + Motheo → Letswai + Metsi
Mohlala oa karabelo pakeng tsa hydrochloric acid le sodium hydroxide:
– HCl(aq) + NaOH(aq) → NaCl(aq) + H₂O(l)
Sebakeng sa ho lekana ha titration, palo ea li-moles tsa HCl e lekana le palo ea li-moles tsa NaOH. Hobane ka bobeli li matla, phetoho ea pH ho potoloha ntlha ea ho lekana hangata e bohale haholo, e leng se etsang hore ho be bonolo ho e lemoha ka sesupo se loketseng.
Khopolo ea lipalo tsa titration e amana haufi-ufi le molarity le stoichiometry. Ka kakaretso, likamano tse sebelisitsoeng ke:
– (M₁ × V₁) / coefficient = (M₂ × V₂) / coefficient
Moo M e leng molarity, V ke bophahamo ba modumo, mme di-coefficient ke di-coefficient tsa karabelo ho ya ka equation ya dikhemikhale (haeba e se 1:1).
Lisebelisoa le Lisebelisoa tse Sebelisitsoeng
Titration ea motheo oa asiti e hloka lisebelisoa tse 'maloa tse tloaelehileng, ho kenyeletsoa:
1. Burette: Sesebelisoa sa ho rotha titrant butle le ho lekanya bophahamo ba modumo ka nepo.
2. Erlenmeyer: Setshelo sa analyte se tjhesetswang ka titration hore se be bonolo ho sisinyeha mme se se ke sa tsholoha habonolo.
3. Phaephe ea volumetric: Ho nka bophahamo bo itseng ba analyte ka nepo.
4. Ema 'me u khomarele: Ho tšoara freette e otlolohile ebile e tsitsitse.
5. Ditshupiso tsa motheo wa asiti: Dintho tse fetolang mmala maemong a itseng a pH.
6. Tharollo e tloaelehileng: Tharollo ea Titrant e nang le mahloriso a tsejoang (mohlala, NaOH e tloaelehileng kapa HCl e tloaelehileng).
Ha e le hantle, ho nepahala ha burette le pipette ho susumetsa haholo liphetho, kahoo li tlameha ho sebelisoa ka nepo 'me palo ea meniscus e tlameha ho nepahala.
Lipontšo le Liphetoho tsa 'Mala
Ditshupiso ke karolo ya bohlokwa ya titration ya motheo wa asiti. Ditshupiso ke metswako e fokolang ya tlhaho e bontshang mebala e fapaneng ka dibopeho tsa yona tsa asiti le tsa motheo. Kgetho ya sesupo e itshetlehile ka mofuta wa asiti le motheo o tekwang, kaha pheletso ya titration e lokela ho etsahala haufi le ntlha ya ho lekana kamoo ho ka kgonehang.
Mehlala ea matšoao a sebelisoang hangata:
– Phenolphthalein (PP): Ha e na mmala maemong a asiti, e fetoha pinki maemong a alkaline (pH e ka ba 8,2–10).
– Methyl lamunu (MO): E khubelu maemong a asiti, e mosehla maemong a alkaline (pH e ka ba 3,1–4,4).
– Bromthymol blue (BTB): E tshehla (e nang le asiti), e tala (e sa nke lehlakore), e putsoa (ea motheo) e nang le pH e ka bang 6,0–7,6.
Ho titrations e matla ea motheo ea asiti-e matla, lipontšo tse ngata li ka sebelisoa hobane keketseho ea pH ntlheng ea ho lekana e bohale haholo. Leha ho le joalo, ho titrations e fokolang ea asiti-e matla kapa ho titrations e matla ea asiti-e fokolang ea motheo, khetho ea lipontšo e tlameha ho ba hlokolosi haholoanyane.
Ntlha ea Tekano le Ntlha ea Qetello
Ha ho ngoloa titration, ho bohlokoa ho khetholla mantsoe a mabeli:
– Ntlha ea ho lekana: Boemo ba khopolo-taba ha li-mole tsa asiti le li-mole tsa motheo li tšoana hantle le stoichiometry ea karabelo.
– Qetello: Boemo bo sebetsang bo tšoauoang ke phetoho 'mala oa sesupo kapa palo e itseng ea pH.
Ntlha ea qetello e lokela ho ba haufi kamoo ho ka khonehang le ntlha ea ho lekana. Phapang pakeng tsa tse peli e bitsoa phoso ea sesupo, e ka amang ho nepahala ha liphetho tsa titration.
Mefuta ea Titration ea Acid-Base
Li-titrations tsa motheo oa asiti li ka aroloa ho latela matla a asiti le motheo o arabelang:
1. Asiti e matla - motheo o matla
Mohlala: HCl e na le titrated ka NaOH. Ntlha ea ho lekana hangata e ba pH e ka bang 7.
2. Asiti e fokolang - motheo o matla
Mohlala: CH₃COOH (acetic acid) e na le titration ka NaOH. Sebakeng sa ho lekana, pH e atisa ho ba kaholimo ho 7 hobane letsoai la motheo (mohlala, sodium acetate) lea thehoa. Lipontšo tse kang phenolphthalein hangata lia loketse.
3. Asiti e matla - motheo o fokolang
Mohlala: HCl e na le titrated ka NH₄OH. pH sebakeng sa equivalence hangata e ka tlase ho 7 hobane letsoai le bopilweng le na le asiti.
4. Asiti e fokolang - motheo o fokolang
Mohlala: asiti ea asetiki e nang le ammonia. Phetoho ea pH ho potoloha ntlha ea ho lekana ha e bohale, kahoo sesupo ha se sebetse hantle; ho khethoa mithara ea pH.
Mehato e Akaretsang ea Titration
Ka kakaretso, ts'ebetso ea titration ea acid-base e kenyelletsa:
1. Hlatsoa burette ka tharollo ea titrant ho thibela ho qhibiliha ha metsi.
2. Tlatsa burette mme o netefatse hore ha ho na dipululana tsa moya ntlheng ya pompo.
3. Nka bophahamo ba moqolo wa analyte ka pipette ya volumetric, ebe o e kenya ka hara flask ya Erlenmeyer.
4. Kenya marotholi a 'maloa a sesupo ho mohlahlobi.
5. Lahlela titrant ho tsoa ho burette ha o ntse o hlohlelletsa flask ea Erlenmeyer butle.
6. Ha o ntse o atamela ntlha ya ho qetela, rotha butle ho qoba ho fetolwa ke mmala.
7. Ngola bophahamo ba titrant bo sebedisitsweng ha ntlha ya ho qetela e fihlelletswe.
8. Pheta titration ho fihlela ho fumanoa liphetho tse tsitsitseng (hangata titration tse tharo tse nang le liphapang tse nyane).
Mehlala ea Ts'ebeliso Bophelong le Indastering
Titration ea motheo oa asiti e na le lits'ebetso tse ngata tsa lefats'e la nnete, mohlala:
– Fumana boemo ba asiti ea asetiki ka har'a asene.
– Leka maemo a alkaline lihlahisoa tsa ho hloekisa kapa sesepa.
– Ho lekanya alkalinity ea metsi tlhahlobong ea tikoloho.
– Taolo ea boleng tlhahisong ea meriana le lik'hemik'hale.
– Fumana hore na litharollo tse tloaelehileng li le ngata hakae laboratoring.
Kaha mokhoa ona o theko e tlase ebile o nepahetse, titration e se e le mokhoa o tloaelehileng oa taolo ea boleng liindastering tse ngata.
Qetello
Titration ea motheo oa asiti ke mokhoa oa tlhahlobo ea volumetric o sebelisoang ho fumana hore na tharollo ea asiti kapa ea motheo e na le bokae ka karabelo ea neutralization. Bohlokoa ba titration ke ho fihlela ntlha ea ho lekana le ho e lemoha ho sebelisoa sesupo kapa meter ea pH. Katleho ea titration e susumetsoa haholo ke litekanyo tse nepahetseng tsa bophahamo, khetho ea sesupo se nepahetseng, le kutloisiso ea litšobotsi tsa li-acid le li-base tse sebelisitsoeng. Ka ho utloisisa mohopolo oa titration ea motheo oa asiti, re ka sebelisa mokhoa ona ka katleho bakeng sa merero ea thuto le ea indasteri, hammoho le tlhahlobo ea letsatsi le letsatsi.
Haeba o batla, nka eketsa mehlala ea mathata a ho bala titration ea acid-base hammoho le lipuisano tsa bona kapa ka etsa mofuta o bonolo oa sengoloa bakeng sa baithuti ba sekolo se phahameng/se phahameng.
