"Acid" yog ib lo lus sib sau ua ke rau cov chav kawm ntawm cov tshuaj sib txuas.
Hauv chemistry, lub ntsiab lus nqaim ntawm cov kua qaub yog: ib qho sib xyaw uas, thaum yaj hauv cov kua dej, ionizes los tsim cov cations uas muaj tsuas yog hydrogen ions. Qhov kev txhais no tau hais los ntawm Arrhenius, thiab lub hauv paus ntsiab lus yog hu ua Arrhenius acid-base theory.
Lub ntsiab txhais ntawm ib qho kua qaub yog: ib yam khoom muaj peev xwm txais tau ib khub ntawm electrons.
Feem ntau cov khoom nyob rau hauv pawg no yog yooj yim soluble nyob rau hauv dej; Txawm li cas los xij, ib qho me me - xws li silicic acid - yog soluble me ntsis. Aqueous daws ntawm acids feem ntau ua hluav taws xob; Lawv cov conductivity yog ncaj qha ntsig txog lawv cov qib ntawm ionization hauv dej. Qee cov kua qaub muaj nyob hauv dej feem ntau ua cov molecules tsis zoo thiab yog li tsis ua hluav taws xob; Lwm tus dissociate rau hauv qhov zoo thiab tsis zoo ions, yog li ua rau hluav taws xob conductivity.
Brønsted-Lowry Acid-Base Theory (Proton Theory): Cov ntsiab lus dav dav posits tias, nyob rau hauv cov tshuaj tiv thaiv tshuaj, txhua yam khoom muaj peev xwm pub tau ib tug proton yog cais raws li ib tug acid, thaum lub converse (ib tug proton txais) yog cais raws li lub hauv paus. Qhov kev txhais no yog ntaus nqi rau JM Brønsted thiab TM Lowry.
Brønsted acidity yog ib lub tswv yim muab los ntawm Brønsted-Lowry txoj kev xav, sawv cev rau cov khoom muaj peev xwm tso tawm cov proton (H⁺). Tshwj xeeb, rau cov khoom HA uas tso tawm H⁺ ion los ua A⁻, nws cov Brønsted acidity yog xam los ntawm qhov sib npaug ntawm cov tshuaj tiv thaiv: HA ⇌ H⁺ + A⁻. Qhov loj dua qhov sib npaug ntawm qhov tsis tu ncua, HA yooj yim tshaj tawm cov proton, thiab yog li ntawd, nws cov Brønsted acidity muaj zog dua.
Lewis Acid-Base Theory: Tshaj tawm los ntawm American chemist GN Lewis, qhov kev tshawb xav no txhais cov kua qaub ua ib yam khoom uas ua raws li cov khoom siv hluav taws xob -pair acceptor- hu ua "Lewis acid." Qhov kev txhais no suav nrog qhov dav dav dua li cov kev xav yav dhau los. Ib qho Lewis acid- cov tshuaj tiv thaiv hauv paus yog cov tshuaj tiv thaiv uas muaj kev sib koom ua ke covalent daim ntawv cog lus ntawm ib qho hluav taws xob -pair acceptor thiab electron -pair donor.
Hard and Soft Acids and Bases (HSAB) Theory: HSAB theory ua hauj lwm raws li kev txuas ntxiv ntawm Lewis acid-base theory. Nyob rau hauv lub moj khaum ntawm HSAB txoj kev xav, ob qho tib si acids thiab cov hauv paus tau muab faib ua ob chav kawm: "nyuaj" thiab "mos."
