Why need autoprotolysis if the PH is greater than 6 ?

Moderators: Chem_Mod, Chem_Admin

Chem_Mod
Posts: 17810
Joined: Thu Aug 04, 2011 1:53 pm
Has upvoted: 405 times

Why need autoprotolysis if the PH is greater than 6 ?

Postby Chem_Mod » Sun Aug 21, 2011 12:05 pm

Why must autoprotolysis need to be taken into account if the pH is greater than 6?

Chem_Mod
Posts: 17810
Joined: Thu Aug 04, 2011 1:53 pm
Has upvoted: 405 times

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

Postby Chem_Mod » Sun Aug 21, 2011 12:05 pm

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.


Return to “Conjugate Acids & Bases”

Who is online

Users browsing this forum: Annie Ye and 1 guest