Cov Acids Tsis Muaj Zog thiab Cov Bases Tsis Muaj Zog: Cov Yam Ntxwv, Piv Txwv, thiab Kev Siv Hauv Lub Neej Txhua Hnub
Pendahuluuan
Hauv kev tshuaj lom neeg, cov kua qaub thiab cov hauv paus yog ob pawg ntawm cov tshuaj uas muaj cov yam ntxwv sib txawv thiab lub luag haujlwm tseem ceeb hauv ntau yam tshuaj lom neeg. Cov kua qaub thiab cov hauv paus tuaj yeem raug cais ua cov muaj zog thiab tsis muaj zog, nyob ntawm lawv lub peev xwm los rhuav tshem cov protons (H⁺) lossis hydroxide ions (OH⁻) hauv cov kua dej. Tsab xov xwm no yuav tham txog cov kua qaub tsis muaj zog thiab cov hauv paus tsis muaj zog kom meej, suav nrog lawv cov yam ntxwv, piv txwv, thiab kev siv txhua hnub.
Cov yam ntxwv ntawm cov kua qaub tsis muaj zog
Cov kua qaub tsis muaj zog yog cov kua qaub uas tsis sib cais tag nrho hauv cov kua dej. Qhov no txhais tau tias lawv tsuas yog tso tawm ib feem ntawm lawv cov protons muaj (H⁺). Qhov no yog qhov sib txawv ntawm cov kua qaub muaj zog, uas sib cais tag nrho. Qib ntawm kev sib cais ntawm cov kua qaub tsis muaj zog yog piav qhia los ntawm qhov kev sib cais ntawm cov kua qaub (Ka), qhov twg tus nqi Ka me dua qhia txog cov kua qaub tsis muaj zog.
Piv txwv ntawm cov kua qaub tsis muaj zog suav nrog acetic acid (CH₃COOH), citric acid (C₆H₈O₇), thiab carbonic acid (H₂CO₃). Cia peb saib qee qhov piv txwv kom ntxaws ntxiv:
1. Acetic Acid (CH₃COOH)
- Qhov chaw: Cov khoom tseem ceeb hauv cov kua txiv hmab.
– Ka: 1.8 × 10⁻⁵.
- Siv: Tshuaj ntxuav hauv tsev, tshuaj tiv thaiv khoom noj, thiab tshuaj reagent hauv cov tshuaj lom neeg organic.
2. Kua Txob Citric (C₆H₈O₇)
– Qhov chaw: Pom muaj nyob rau hauv cov txiv hmab txiv ntoo citrus xws li txiv qaub thiab txiv kab ntxwv.
– Ka: Txawv vim tias citric acid muaj peb protons uas tuaj yeem tso tawm, nrog Ka₁ = 7.4 × 10⁻⁴.
- Siv: Ua ib qho khoom noj khoom haus preservative, acidifier, thiab hauv kev tsim cov khoom siv rau daim tawv nqaij.
3. Cov kua qaub carbonic (H₂CO₃)
– Qhov Chaw: Tsim los ntawm cov tshuaj carbon dioxide hauv dej, xws li hauv cov dej haus uas muaj carbonated.
– Ka: Ka₁ = 4.3 × 10⁻⁷.
- Siv: Tswj cov kua qaub-puag hauv cov ntshav, cov dej haus uas muaj pa roj carbonated.
Cov yam ntxwv ntawm Cov Hauv Paus Tsis Muaj Zog
Lub hauv paus tsis muaj zog yog lub hauv paus uas tsis tawg tag nrho hauv cov kua dej. Ib yam li cov kua qaub tsis muaj zog, cov hauv paus tsis muaj zog kuj muaj lub hauv paus sib xyaw ua ke muaj zog thiab lub hauv paus sib cais tas mus li (Kb), qhov twg tus nqi Kb me dua qhia txog lub hauv paus tsis muaj zog.
Piv txwv ntawm cov hauv paus tsis muaj zog suav nrog ammonia (NH₃), methylamine (CH₃NH₂), thiab dej (H₂O). Nov yog qee cov hauv paus tsis muaj zog kom ntxaws ntxiv:
1. Ammonia (NH₃)
– Qhov chaw: Tsim los ntawm kev lwj ntawm cov organic matter thiab muaj nyob rau hauv cov khoom siv tu tsev.
– Kb: 1.8 × 10⁻⁵.
- Siv: Chiv, tshuaj ntxuav, thiab dej txias hauv cov tshuab ua kom txias ammonia.
2. Methylamine (CH₃NH₂)
– Qhov chaw: Tsim los ntawm cov txheej txheem fermentation thiab ua ib qho reagent hauv kev tsim tshuaj lom neeg.
– Kb: 4.4 × 10⁻⁴.
- Siv: Kev tsim cov tshuaj tua kab, tshuaj, thiab cov xim.
3. Dej (H₂O)
- Qhov chaw: Tshwm sim hauv ntuj tsim.
- Kb: Me heev, vim tias dej ua haujlwm ua lub hauv paus tsis muaj zog heev hauv cov tshuaj tiv thaiv autodissolving.
- Siv: Cov kuab tshuaj rau kev tshuaj lom neeg, haus dej, thiab hauv lub neej txhua hnub.
Cov Tshuaj Tiv Thaiv Acid Tsis Muaj Zog thiab Cov Tshuaj Tiv Thaiv Base Tsis Muaj Zog
Cov tshuaj tiv thaiv ntawm cov kua qaub tsis muaj zog thiab cov hauv paus tsis muaj zog feem ntau tsis tshua muaj cua sov dua li cov tshuaj tiv thaiv ntawm cov kua qaub muaj zog thiab cov hauv paus muaj zog. Cov tshuaj tiv thaiv no tsim cov ntsev thiab dej hauv cov txheej txheem hu ua neutralization. Txawm li cas los xij, neutralization ntawm cov kua qaub tsis muaj zog thiab cov hauv paus tsis muaj zog tsis tas li tsim cov tshuaj tsis muaj zog vim tias cov khoom tshwm sim tuaj yeem muaj cov khoom acidic lossis basic nyob ntawm lub zog ntawm cov kua qaub thiab hauv paus.
Piv txwv li, cov tshuaj tiv thaiv ntawm acetic acid (ib qho kua qaub tsis muaj zog) thiab ammonia (ib qho tsis muaj zog) tsim cov ammonium acetate:
\[ \text{CH}_3\text{COOH} + \text{NH}_3 \rightarrow \text{CH}_3\text{COO}^- + \text{NH}_4^+ \]
Cov Ntawv Thov Hauv Lub Neej Txhua Hnub
1. Kev tswj hwm pH hauv lub cev
– Carbonic acid thiab bicarbonate (conjugate bases) ua lub luag haujlwm tseem ceeb hauv cov ntshav buffer system uas ua kom cov ntshav pH nyob rau hauv qhov ntau ntawm kwv yees li 7.4.
2. Kev Lag Luam Khoom Noj thiab Dej Haus
– Citric acid siv rau hauv kev lag luam khoom noj thiab dej haus kom ntxiv qhov saj thiab ua ib yam khoom tiv thaiv. Ammonia siv rau hauv qee cov txheej txheem fermentation.
3. Kev Ntxuav Tsev Neeg
- Cov tshuaj xws li acetic acid hauv vinegar yog siv los ua cov tshuaj ntxuav ntuj, thaum ammonia pom muaj nyob rau hauv cov khoom ntxuav kom tshem tawm cov xim av thiab cov ntxhiab tsw.
4. Kev Ua Liaj Ua Teb
- Ammonia yog ib qho tseem ceeb hauv kev tsim cov chiv nitrogen, uas yog qhov tseem ceeb rau kev loj hlob ntawm cov nroj tsuag.
5. Tshuaj thiab Tshuaj Kho Mob
- Ntau cov tshuaj siv cov derivatives ntawm cov weak acids thiab weak bases los ua kom muaj txiaj ntsig zoo dua lossis tswj pH ntawm cov tshuaj.
Xaus
Cov kua qaub tsis muaj zog thiab cov hauv paus tsis muaj zog ua lub luag haujlwm tseem ceeb hauv ntau yam ntawm lub neej, los ntawm kev ua haujlwm ntawm lub cev mus rau kev siv hauv kev lag luam. Txawm hais tias lawv tsis sib cais tag nrho hauv cov kua dej, lawv lub peev xwm los koom nrog cov tshuaj lom neeg rau ntau yam kev siv qhia txog qhov tseem ceeb ntawm kev nkag siab txog cov yam ntxwv no. Los ntawm kev nkag siab txog cov kua qaub tsis muaj zog thiab cov hauv paus zoo dua, peb tuaj yeem siv lawv zoo dua hauv ntau qhov chaw.
