Qhov kwv yees pKa ntawm thiol yog dab tsi?

2024 Tus sau: Miles Stephen | [email protected]. Kawg hloov kho: 2023-12-15 23:36

6.4

Kuj nug tias, pKa ntawm thiol yog dab tsi?

Thiols yog acidic ntau dua li cawv los ntawm qhov nruab nrab ntawm li 5 pKa units los yog li ntawd ( pKa txog 11 rau lub thiol duab hauv qab no). Nco ntsoov tias pKa yog logarithmic, yog li ntawd txhais tau tias lawv nyob li ntawm 10⁵ lub sij hawm ntau acidic.

Kuj Paub, pKa ntawm ib qho aldehyde yog dab tsi? C-H daim ntawv cog lus tsis yog acidic. Vim hais tias ntawm resonance stabilization ntawm conjugate puag, α-hydrogen nyob rau hauv ib qho aldehyde (tsis pom hauv daim duab saum toj no) yog acidic ntau dua, nrog pK_ib nyob ze 17, piv rau acidity ntawm ib txwm alkane (pK_ib txog 50).

Tom qab ntawd, qhov kwv yees pKa tus nqi ntawm ethanol yog dab tsi?

Thaum cov compounds zoo li tsis muaj zog acidic hauv dej Raws li ethanol, peb pib ntsuas lawv cov acidity los ntawm lawv cov pKa qhov tseem ceeb es tsis yog lawv cov nqi Ka. Ethanol tus nqi pKa yog kwv yees li 15.9.

PKa sawv rau dab tsi?

Cov ntsiab lus tseem ceeb: pKa Lus Txhais The pKa tus nqi yog ib txoj kev siv los qhia lub zog ntawm cov kua qaub. pKa yog lub cav tsis zoo ntawm cov kua qaub dissociation tas li los yog Ka tus nqi. Ib qho qis pKa tus nqi qhia tias muaj zog acid. Ntawd yog, tus nqi qis dua qhia tias cov kua qaub ntau dissociates hauv dej.