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Why need autoprotolysis if the PH is greater than 6 ?

Posted: Sun Aug 21, 2011 12:05 pm
by Chem_Mod
Why must autoprotolysis need to be taken into account if the pH is greater than 6?

Re: Why need autoprotolysis if the PH is greater than 6 ?

Posted: Sun Aug 21, 2011 12:05 pm
by Chem_Mod
In the pH range of ~6-8, the hydronium ion concentration provided by the weak acid is comparable to that of the autoprolysis of water. Because of this, the latter cannot be ignored because neither one of the hydronium ion sources is dominant enough to ignore the other. To take into account the autoprolysis of water, just use Kw = [H3O+][OH-] = 10^-14.