mjl1717
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10%
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Smell the coffee! "Is That an Osler move??"
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| stendl
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answer: is 90%. but how?
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| mjl1717
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Topics: 959
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My MISTKAKE , I had it the opposite way which is WRONG.Only the nonionized form,which is uncharged and LIPOD soluble crosses boundaries.
pH-pKa -2 -1 0 +1 +2 pH-pKa= x
weak
acid%non 2.5-3.5= -1
ionized 99 90 50 10 1
At-1 90% is in lipod form
I apologize
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Smell the coffee! "Is That an Osler move??"
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| stendl
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yes, thanks
but how did you calculate?
you told me the possible answer 99- 90-.... and logic how did you find the correct answer 90?
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| neevyg
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how'd u get that?
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| Ouli Maty
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Kaplan has a wonderful table about this. I know we should be able to calculate this using the Henderson-hasselbalch equation but in the exam, I wouldn't like to have to calculate too much. So I just try to remember the figures.
Absorbed form is the non ionized one ( weak acid or weak base)
pH - pKa= -2 ; -1; 0; 1; 2 correspond respectively to unionized form of
weak acid 99%; 90%; 50%; 10%; 1% and the opposite with
weak base 1%, 10%; 50%; 90%; 99%.
Weak acid + weak base = 100%
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deep breathing...
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