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Topic: Acidic buffer  (Read 3269 times)

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Offline will_L

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Acidic buffer
« on: May 27, 2012, 08:12:28 PM »
Under what conditions can an acidic buffer have a pH more than 7?
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Offline sjb

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Re: Acidic buffer
« Reply #1 on: May 28, 2012, 12:20:37 AM »
Quote from: will_L on May 27, 2012, 08:12:28 PM
Under what conditions can an acidic buffer have a pH more than 7?

What is the definition of an acid?
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Offline Borek

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Re: Acidic buffer
« Reply #2 on: May 28, 2012, 03:18:48 AM »
More importantly, what do you mean by "acidic buffer"?
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Offline AWK

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Re: Acidic buffer
« Reply #3 on: May 28, 2012, 04:52:25 AM »
Quote from: will_L on May 27, 2012, 08:12:28 PM
Under what conditions can an acidic buffer have a pH more than 7?
Each buffer solution consists of an acid and its conjugated base.
If Kb of base is significantly greater than Ka of acid then pH is greater than 7.
"Acidic buffer" comes from Arrhenius theory - "buffer contains a weak  acid and its salt..." , eg HCN and NaCN.
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Offline will_L

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Re: Acidic buffer
« Reply #4 on: May 30, 2012, 08:53:12 PM »
according to the definition, acidic buffer is made by mixing a weak acid with the sodium salt of that acid,and is supposed to have a pH less than 7, but i came across with a quesiton having a pH slightly higher than 7 in the acidic buffer...

i think that's the answer to my question...thanks a lot
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Offline AWK

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Re: Acidic buffer
« Reply #5 on: May 31, 2012, 07:03:04 AM »
A buffer ocontainig 0.1 m HCN AND 0.1 M NaCN will shoh pH slightly over 9.
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