Qhov txawv ntawm Alkalinity thiab Basicity

2024 Tus sau: Alex Aldridge | [email protected]. Kawg hloov kho: 2023-12-17 13:40

Qhov Tseem Ceeb - Alkalinity vs. Basicity

Ob lo lus "alkalinity" thiab "basicity" yog qhov tsis meej pem. Feem coob ntawm cov neeg paub tias muaj qhov sib txawv ntawm ob qhov kev txwv no, tab sis tsuas yog qee tus ntawm lawv tuaj yeem txhais tau raug. Qhov sib txawv tseem ceeb ntawm ob lo lus no tau piav qhia zoo tshaj plaws hauv lawv cov lus txhais. Basicity yog ib qho kev ntsuas uas ncaj qha nyob ntawm pH nplai thiab alkalinity yog ntau npaum li cas acid yuav tsum tau txo cov pH rau hauv ib qho tseem ceeb acid tus nqi; nws tseem hu ua lub peev xwm buffering ntawm lub cev dej. Hauv lwm lo lus, tus nqi pH ntawm cov kev daws teeb meem sib txawv ntawm 7-14; qhov twg cov kev daws teeb meem nrog cov nqi pH siab yog qhov yooj yim dua. Ob leeg muaj ob peb lub ntsiab lus, tab sis lub tswv yim dav dav zoo ib yam.

Alkalinity yog dab tsi?

Alkalinity yog ib qho tseem ceeb tshaj plaws hauv cov dej hauv dej, thiab nws tseem ceeb heev rau cov kab mob hauv dej. Alkalinity ntsuas lub peev xwm ntawm lub cev dej kom tsis txhob muaj cov kua qaub thiab cov hauv paus. Hauv lwm lo lus, nws yog lub peev xwm buffering ntawm lub cev dej kom tswj tau tus nqi pH ntawm tus nqi ruaj khov. Cov dej uas muaj bicarbonates (HCO₃^-), carbonates (CO₃2- ^{) thiab hydroxides (OH}–^{) yog qhov tsis zoo; lawv tuaj yeem ua ke nrog H}+ ^{ions hauv dej kom nce pH (ua kom yooj yim dua) ntawm cov dej. Thaum alkalinity tsawg dhau (buffering muaj peev xwm tsawg), cov kua qaub ntxiv rau hauv lub cev dej txo nws cov pH kom ntau dua acidic nqi.}

Dab tsi yog qhov yooj yim?

Basicity yog cov cuab yeej ntawm cov hauv paus, ntsuas hauv pH nplai. Bases yog cov khoom sib xyaw uas muaj pH saum toj no 7; los ntawm pH=8 (tsis yooj yim) rau pH=18 (ntau dua). Lub hauv paus ntawm ib qho kev sib xyaw tuaj yeem txhais tau peb txoj kev sib txawv. Raws li Arrhenius txoj kev xav, cov hauv paus yog cov tshuaj uas cuam tshuam rau hauv cov dej nruab nrab uas ua rau OH^– ions. Hauv Bronsted-Lowry txoj kev xav, proton txais yog hu ua bases. Raws li Lewis txoj kev xav, ib qho hluav taws xob khub pub dawb yog hu ua lub hauv paus. Basicity yog lub zog ionization los tsim OH^{– ions, muaj peev xwm lees txais protons lossis muaj peev xwm pub dawb electrons.}

Thomas Martine Lowry – Bronsted–Lowry Theory

Qhov txawv ntawm Alkalinity thiab Basicity yog dab tsi?

Txhais ntawm Alkalinity thiab Basicity:

Alkalinity: Ob peb lub ntsiab lus muaj.

Alkalinity yog cov kua qaub nruab nrab muaj peev xwm ntawm cov kuab tshuaj hauv cov qauv dej ntsuas hauv milliequivalents ib liter.

Cov sum ntawm titratable carbonate thiab noncarbonate chemical hom nyob rau hauv ib tug lim dej qauv.

Lub peev xwm ntawm dej kom tsis txhob muaj kua qaub.

Lub peev xwm buffering ntawm cov dej kom tswj tau qhov pH ruaj khov, tsis hloov nws tus nqi pH, thaum cov kua qaub ntxiv.

Basicity: Peb txoj kev xav yog siv los txhais cov kua qaub thiab qhov pib.

Arrenhius: Bases yog hom ionize los tsim OH^– hauv dej. Basicity nce raws li lawv ionize ntau, muab OH^{–hauv dej.}

Bronsted-Lowry: Proton (H^{+) lees txais yog hu ua bases.}

Lewis: Cov khub hluav taws xob muab hu ua lub hauv paus.

Yam cuam tshuam rau Alkalinity thiab Basicity:

Alkalinity: Alkalinity tsis nyob ntawm tus nqi pH; Cov dej hauv dej tuaj yeem muaj qis dua (muaj kua qaub) lossis siab dua (pH) tus nqi nrog tus nqi siab dua rau alkalinity. Alkalinity yog txiav txim siab los ntawm ntau yam xws li pob zeb, av, ntsev thiab qee yam kev lag luam (cov dej khib nyiab uas muaj xab npum thiab cov tshuaj ntxuav tes yog alkaline) los ntawm tus txiv neej. Piv txwv li, cov cheeb tsam uas limestone (CaCO_{3) muaj ntau heev tuaj yeem muaj dej alkaline ntau dua.}

Basicity: Cov yam tseem ceeb cuam tshuam rau lub hauv paus ntawm ib qho chaw sib txawv nyob ntawm qhov txhais ntawm qhov pib. Piv txwv li, ob qho hluav taws xob muaj nyob ntawm lub hauv paus nyob ntawm peb yam.

Electronegativity: CH3- > NH2- > HO- > F-

Thaum xav txog cov atoms nyob rau hauv tib kab hauv lub sij hawm lub sij hawm, feem ntau electronegative atom muaj lub hauv paus siab dua.

Size: F- > Cl- > Br- > I-

Thaum xav txog ib kab ntawm lub rooj sib tham, qhov loj ntawm lub atom muaj tsawg dua electron ceev thiab nws tsis yooj yim.

Resonance: RO- >RCO^2-

Molecules uas muaj cov qauv resonance ntau dua yog qhov yooj yim dua, vim tias muaj hluav taws xob tsawg dua li qhov tsis zoo hauv zos.