Dab tsi yog pKa ntawm cov kua qaub muaj zog?
Dab tsi yog pKa ntawm cov kua qaub muaj zog?

Video: Dab tsi yog pKa ntawm cov kua qaub muaj zog?

Video: Dab tsi yog pKa ntawm cov kua qaub muaj zog?
Video: Leela Xiong |Dab Tsi Yog Koj Tu Npau Suav| 2024, Kaum ib hlis
Anonim

Cov kua qaub muaj zog yog txhais los ntawm lawv cov pKa. Cov kua qaub yuav tsum muaj zog nyob rau hauv aqueous tov tshaj ib hydronium ion , yog li nws pKa yuav tsum qis dua li ntawm a hydronium ion . Yog li ntawd, muaj zog acids muaj pKa ntawm <-174.

Xav txog qhov no, pKa cuam tshuam li cas rau acid zog?

Re: Kev sib raug zoo ntawm pka ua , ka, thiab acidity zog Raws li qhov tshwm sim, cov tshuaj tiv thaiv yuav nyiam ua kom tiav kev sib cais ntawm cov tsis muaj zog kua qaub , yog li muab nws muaj peev xwm pub dawb rau proton (muaj zog kua qaub ). pKa yog qhov opposite ho, qhov loj dua pKa , lub weaker lub kua qaub yog.

Tsis tas li ntawd, pKa ntawm cov kua qaub tsis muaj zog yog dab tsi? Yog li ntawd, pKa tau qhia raws li qhov ntsuas los qhia txog acidity ntawm tsis muaj zog acids , qhov twg pKa yog txhais raws li nram no. Piv txwv li, Ka tas li rau acetic kua qaub (CH3TZS) is 0.0000158 (= 10-4.8), tab sis pKa qhov tsis tu ncua yog 4.8, uas yog ib qho yooj yim qhia. Tsis tas li ntawd, qhov me me pKa tus nqi, lub zog kua qaub.

Cov lus nug tseem yog, pKa ntawm lub hauv paus muaj zog yog dab tsi?

Methyllithium, CH3Li, yog ib qho zoo kawg lub hauv paus muaj zog . Conversely, acetylide ion, HCC (–) yog muaj zog txaus kom zoo deprotonate tej acid nrog a pKa qis dua ~ 25, thiab acetate ion (CH3COO(–)) tseem tsis muaj zog, tsuas yog tuaj yeem deprotonate cov kua qaub nrog ib qho pKa qis dua 5.

Cov kua qaub puas muaj pKa siab lossis qis?

Re: pKa thiab nws txoj kev sib raug zoo nrog npaum li cas acidic ib yam dab tsi yog -> 10^- pKa = Ka. A qis pka txhais tau tias tus nqi Ka yog siab dua thiab a siab dua Ka nqi txhais tau tias kua qaub dissociates yooj yim dua vim nws muaj ib Qhov loj dua concentration ntawm Hydronium ions (H3O+).

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