Key Difference – pH vs pOH
Cov ntsiab lus pH thiab pOH yog siv los qhia cov nyiaj H+ thiab OH– ions tam sim no hauv cov tshuaj aqueous. Cov kab lus no tau muab raws li qhov ntsuas qhov tseem ceeb ntawm qhov concentration ntawm solute. pH hais txog "muaj peev xwm ntawm hydrogen". Nws tuaj yeem siv los txiav txim siab seb cov tshuaj puas yog acidic, yooj yim lossis nruab nrab. Hauv qhov sib piv, pOH yog ib qho kev ntsuas ntawm hydroxide ion (OH–) concentration. Qhov sib txawv tseem ceeb ntawm pH thiab pOH yog qhov pH yog ntsuas ntawm hydrogen ions thaum pOH yog ntsuas ntawm hydroxide ions.
pH yog dab tsi?
pH yog ib daim duab qhia txog acidity lossis alkalinity ntawm cov tshuaj ntawm cov logarithmic scale uas 7 yog nruab nrab. Cov nqi qis dua 7 yog cov kua qaub ntau dua thaum cov nqi siab dua alkaline. Cov pH yog sib npaug rau −log10 c, qhov twg c yog cov hydrogen ion concentration hauv moles ib liter.
PH ntsuas pH khiav ntawm 1 txog 14. Cov pH qhov tseem ceeb 1 txog 6 tau lees paub tias yog acidic pH qhov tseem ceeb. Cov pH qhov tseem ceeb ntawm 8 mus rau 14 tau lees paub tias yog pH qhov tseem ceeb. Lub pH 7 yog suav tias yog qhov nruab nrab pH. Piv txwv li, cov kua qaub muaj zog muaj pH tus nqi ze pH=1 thaum lub hauv paus muaj zog muaj pH tus nqi ze pH=14. Lub "p" hauv lo lus pH hais txog qhov tsis zoo logarithm. Feem ntau, qhov tsis zoo logarithm ntawm hydrogen ion concertation (los yog pH) yog siv es tsis txhob siv cov concentration ntawm hydrogen ions. Tias yog vim li cas, feem ntau ntawm cov sij hawm, qhov concentration ntawm hydrogen ions tsawg heev los yog loj heev, yog li, siv pH ua kom yooj yim rau kev ua hauj lwm nrog xws li me me los yog loj qhov tseem ceeb.
Daim duab 01: pH Scale
Hauv cov tshuaj aqueous, cov dej molecules dissociate rau hauv hydrogen ions thiab hydroxide ions. Yog li ntawd, txhua lub cev dej ntuj muaj ib qho pH nqi. Lub pH ntawm ib qho system yog muab los ntawm qhov sib npaug hauv qab no.
pH=−log10 [H+
Muaj cov ntsuas hu ua pH ntsuas uas siv los qhia qhov kawg ntawm cov tshuaj tiv thaiv acid-base. Cov ntsuas no muaj peev xwm hloov cov xim ntawm cov tshuaj tiv thaiv nruab nrab nrog kev hloov ntawm pH. Piv txwv li, qhov taw qhia phenolphthalein muaj xim liab hauv pH qhov tseem ceeb (txog pH=10.0), tab sis nws tsis muaj xim nyob ib ncig ntawm pH=8.3.
pOH yog dab tsi?
pOH yog ntsuas ntawm hydroxide ion (OH–) concentration. Yog li, pOH yog ib qho kev ntsuas ntawm alkalinity ntawm kev daws. Lub "p" hauv lo lus pOH hais txog qhov tsis zoo logarithm. Yog li cov pOH yog qhov tsis zoo logarithm ntawm hydroxide ion concentration hauv cov tshuaj.
pH=−log10 [OH–
Daim duab 02: Kev sib piv ntawm pH thiab pOH Nplai
Vim tias lo lus no muab cov naj npawb ntawm hydroxide ions tam sim no hauv cov kua dej, nws yog qhov ntsuas ntawm qhov pib (alkalinity). Piv txwv li, pOH tus nqi tsawg dua pOH=7 (ntawm 25oC) yog alkaline. Tom qab ntawd, yog tias cov tshuaj muaj pOH tus nqi nyob nruab nrab ntawm 1 txog 6, cov tshuaj muaj alkaline ntau dua. pOH=7 yog suav tias yog nruab nrab. Tab sis pOH tus nqi siab dua 7 tau lees paub tias yog acidic.
Kev sib txheeb ntawm pH thiab pOH yog dab tsi?
Rau qhov kev sib cais ntawm dej, qhov kev sib cais tsis tu ncua yog muab raws li hauv qab no.
H2O ⇆ H+ + OH–
Kw=[H+][OH–
Qhov twg kw yog qhov sib txawv ntawm cov dej, [H+] yog hydrogen ion concertation thiab [OH–] yog hydroxide ion concentration. Tab sis rau cov dej ntshiab, [H+]=[OH–]=1×10-7 mol / L. tom qab ntawd, thaum qhov tsis zoo logarithms raug coj mus rau txhua lub sij hawm hauv kab zauv saum toj no,
pKw=pH + pOH
pKw=7 + 7
pKw=14
yog li yog tias tsuas yog pH paub, tus nqi pOH tuaj yeem tau txais hu nkauj saum kev sib raug zoo.
Txawm li cas los xij, hauv pH thiab pOH nplai, 7 yog nruab nrab.
Qhov txawv ntawm pH thiab pOH yog dab tsi?
pH vs pOH |
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| pH qhia txog acidity lossis alkalinity ntawm kev daws ntawm qhov ntsuas logarithmic uas 7 yog nruab nrab. | pOH yog ntsuas ntawm hydroxide ion (OH–) concentration. pOH=7 suav tias yog nruab nrab |
| pH muab qhov tsis zoo logarithm ntawm hydrogen ion concentration. | pOH muab qhov tsis zoo logarithm ntawm hydroxide ion concentration. |
| Acidic nuj nqis | |
| pH nplai muab cov kua qaub ntawm 1 txog 6. | pOH nplai muab cov kua qaub ntawm 8 txog 14. |
| Alkaline Values | |
| pH nplai muab qhov tseem ceeb ntawm 8 txog 14. | pOH nplai muab qhov tseem ceeb ntawm 1 txog 6. |
Summary – pH vs pOH
pH thiab pOH yog ob nqe lus siv los qhia txog acidity lossis alkalinity ntawm cov tshuaj. Qhov sib txawv tseem ceeb ntawm pH thiab pOH yog pH yog ntsuas ntawm hydrogen ions thaum pOH yog ntsuas ntawm hydroxide ions.
Download the PDF of pH vs pOH
Koj tuaj yeem rub tawm PDF version ntawm kab lus no thiab siv nws rau offline hom phiaj raws li daim ntawv ceeb toom. Thov rub tawm PDF version ntawm no: Qhov txawv ntawm pH thiab pOH
