Ama-Arrhenius Acids kanye Nezisekelo: Ukwembula Izisekelo ZeKhemistri
Kumakhemikhali, imiqondo yama-asidi nezisekelo iyizisekelo ezibalulekile ezisenza sikwazi ukuqonda ukusabela okuhlukahlukene kwamakhemikhali, kokubili ezindaweni zelebhu kanye nasempilweni yansuku zonke. Enye yezinkolelo-mbono zokuqala neziyisisekelo zokuhlukanisa ama-asidi nezisekelo yasungulwa nguSvante Arrhenius ngasekupheleni kwekhulu le-19. Le nkolelo-mbono, eyaziwa ngokuthi i-Arrhenius Theory of Acids and Bases, inikeza umbono oyisisekelo wezakhiwo zamakhemikhali zama-asidi nezisekelo ngokusekelwe ekuziphatheni kwazo kwe-ionic. Kulesi sihloko, sizohlola imiqondo eyisisekelo yale nkolelo-mbono, imiphumela yayo, kanye nokufaneleka kwayo kanye nokusetshenziswa kwayo ezweni lanamuhla.
Imiqondo Eyisisekelo Yenkolelo-mbono Ka-Arrhenius
USvante Arrhenius, isazi samakhemikhali saseSweden, wawina umklomelo weNobel kuKhemistri ngo-1903 ngomsebenzi wakhe kukhemistri ye-electrolytic. Umnikelo wakhe oyinhloko embonweni wama-acid nezisekelo kwakuwukuhlonza nokuhlela ama-compound ngokusekelwe ekhonweni lawo lokuhlukana nesisombululo samanzi.
Ngokusho kwe-Arrhenius Acid Base Theory:
1. I-Arrhenius Acid: I-asidi iyinhlanganisela ethi, uma incibilikiswa emanzini, ikhiqize ama-ion e-hydrogen (H+). Izibonelo ezivamile zama-Arrhenius acid zifaka phakathi i-hydrochloric acid (HCl), ehlukana emanzini ibe ama-ion e-H+ kanye ne-chloride (Cl-).
I-HCl → H+ + Cl-
2. Isisekelo se-Arrhenius: Isisekelo siyinhlanganisela ethi, uma incibilikiswa emanzini, ikhiqize ama-ion e-hydroxide (OH-). Izibonelo ezivamile zama-base e-Arrhenius zifaka i-sodium hydroxide (NaOH), ehlukana emanzini ibe yi-Na+ kanye ne-OH-.
I-NaOH → I-Na+ + I-OH-
Le mbono inikeza isisekelo esilula kodwa esinamandla sokuhlonza nokuqonda izakhiwo zama-asidi nezisekelo ngokusekelwe emikhiqizweni yazo yokuhlukaniswa emanzini.
Ukusabela Kokungathathi-hlangothi
Omunye wemibono ebalulekile evela ku-Arrhenius Acid-Base Theory ukusabela kokungaguquguquki, lapho i-asidi nesisekelo zisabela khona ukuze zakhe amanzi nosawoti. Ngokuvamile, ukusabela kokungaguquguquki kungachazwa kanje:
I-H+ (kusukela ku-asidi) + OH- (kusukela esisekelweni) → I-H2O (amanzi)
Isibonelo, ukusabela phakathi kwe-hydrochloric acid (HCl) ne-sodium hydroxide (NaOH) kukhiqiza amanzi kanye ne-sodium chloride (NaCl):
I-HCl + NaOH → H2O + NaCl
Ukusabela kokungathathi hlangothi kuyisisekelo sezinqubo eziningi zamakhemikhali ezimbonini, kanye nokusabela okuhlukahlukene kwezinto eziphilayo kanye nokwezinto eziphilayo ezintweni eziphilayo.
Ukulinganiselwa kwe-Arrhenius Theory
Nakuba i-Arrhenius Acid-Base Theory inikeza ukuqonda okuyisisekelo nokuwusizo kakhulu, inemikhawulo eminingana. Umkhawulo omkhulu owodwa ukuthi usebenza kuphela ekuphenduleni ezixazululweni zamanzi futhi awukwazi ukuchaza izakhiwo zama-asidi nezisekelo ezixazululweni ezingezona ezamanzi noma esimweni segesi.
Isibonelo, i-ammonia (NH3) ayihambisani nencazelo ye-Arrhenius yesisekelo ngoba ayikhiqizi i-OH- ngqo emanzini. Kodwa-ke, siyazi ukuthi i-ammonia ingasebenza njengesisekelo ngoba ingamukela ama-ion e-H+ ukwakha ama-ion e-ammonium (NH4+):
I-NH3 + H2O → I-NH4+ + OH-
Ithiyori ka-Arrhenius ayikwazi futhi ukuchaza ukuziphatha kwamakhemikhali athile angama-amphoteric, okungukuthi amakhemikhali angasebenza njenge-asidi kanye nesisekelo, njengamanzi (H2O).
Ukuthuthukiswa Kwethiyori Esekelwe Ku-Acid
Ukuze banqobe ukulinganiselwa kwe-Arrhenius Acid-Base Theory, ososayensi kamuva bathuthukisa i-theory ejwayelekile nehlanganisa wonke umuntu. Imibono emibili eyinhloko eyavela njengentuthuko ye-Arrhenius Acid-Base Theory yi-Brønsted-Lowry Theory kanye ne-Lewis Theory.
1. Ithiyori kaBrønsted-Lowry: Yethulwa nguJohannes Nicolaus Brønsted noThomas Martin Lowry ngo-1923, le thiyori ichaza ama-acid njengabanikeli be-proton (H+) kanye nezisekelo njengabamukeli be-proton. Le thiyori ifaka phakathi ngoba ayigcini nje ngezixazululo zamanzi. Isibonelo:
– I-Asidi: i-HCl (umnikeli we-H+)
– Isisekelo: NH3 (H+ receptor)
Ukusabela: HCl + NH3 → NH4+ + Cl-
2. Ithiyori kaLewis: UGilbert N. Lewis waphakamisa ithiyori yesisekelo se-acid ejwayelekile ngo-1923, echaza ama-acid njengabamukeli be-electron-pair kanye nezisekelo njengabanikeli be-electron-pair. Le ncazelo ihlanganisa ukusabela okuningi kwamakhemikhali okungachazwanga yi-Arrhenius noma i-Brønsted-Lowry Theories. Isibonelo:
– I-Acid: BF3 (isamukeli se-electron pair ngenxa yokuntuleka kwe-electron pair)
– Isisekelo: I-NH3 (umnikeli we-electron pair ngoba ine-electron pair yamahhala)
Ukusabela: BF3 + NH3 → F3B-NH3
Lezi zinkolelo-mbono zigcizelela ukudluliselwa kwama-proton nama-electron pairs, okunikeza umbono ophelele ngokuziphatha kwama-asidi nezisekelo.
Ukusetshenziswa kwe-Arrhenius Acid-Base Theory
Naphezu kwemingcele yayo, izimiso eziyisisekelo ze-Arrhenius Acid-Base Theory zisasebenza futhi zibalulekile ezisetshenziswayo eziningi ezisebenzayo nezezimboni. Nazi ezinye izibonelo:
1. Imboni Yamakhemikhali: Ekwenziweni kwemikhiqizo yansuku zonke efana nezinsipho, umanyolo, namanye amakhemikhali ezimboni, ukuhlonza nokusetshenziswa kwama-asidi nezisekelo kubalulekile.
2. Ukuhlaziywa Kwamakhemikhali: Le mbono ibaluleke kakhulu ekulinganisweni kwe-acid-base, inqubo yokuhlaziya ngobuningi esetshenziswa ukunquma ukuhlushwa kwesisombululo se-acid noma se-base.
3. I-Biology kanye Nezokwelapha: Ukuqonda ukuthi ama-acid kanye nezisekelo kuhlangana kanjani emzimbeni womuntu kubalulekile emikhakheni ye-biochemistry kanye ne-physiology, njengokugcina i-pH yegazi izinzile.
4. Indawo: Ukuqapha i-pH yamanzi nomhlabathi kubaluleke kakhulu ukuze kulondolozwe ibhalansi yendawo kanye nempilo yezinto eziphilayo.
5. Ukwelashwa Kwamanzi: Le mbono isetshenziselwa ukwelashwa kwamanzi angcolile kanye namanzi okuphuza ukuqinisekisa ukuthi i-pH ingaphakathi kwebanga eliphephile.
Isiphetho
Ithiyori ye-Arrhenius acid-base ingase ibe enye yezinkolelo-mbono eziyisisekelo zamakhemikhali, kodwa isasebenza futhi inikeza isisekelo esiqinile sokutadisha okwengeziwe ngezimpendulo ze-acid-base. Naphezu kokulinganiselwa kwayo, umqondo ka-Arrhenius usebenze njengetshe elibalulekile lokuthuthukiswa kweminye imibono ye-acid-base, njengoBrønsted-Lowry noLewis. Ngokuqonda lezi zimiso eziyisisekelo, singaqonda kalula ubunzima nobuhle bezimpendulo zamakhemikhali ezenzeka nxazonke zethu nsuku zonke.
