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Titrations and Equivalence Points

Discussion in 'Pre-Medical - MD' started by TripleDegree, Apr 10, 2004.

  1. TripleDegree

    TripleDegree Joker Doctor
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    Another question - as test day approaches and my BP inches upwards.... (time to stimulate my ADHRH)

    Anyway - is there an intuitive way of understanding equivalence and half-equivalence points? I understand the technical definition, but find it really hard to solve problems since I guess I don't really understand the concept. And when it comes to diprotic acids, I am often clueless.

    Any tidbits would be welcomed
     
  2. Fermata

    Fermata Hold me.
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    When you say "biprotic", are you referring to amphiprotic or polyprotic?
     
  3. XCanadianRagwee

    XCanadianRagwee Membership Revoked
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    those were fun...until some decides to spray the crap everywhere.

    then the times of blowing crap up in cehmistry. Nothing like getting otu early and borrowing someone elses notes because I "accidently" let the pressure build up to much and cause a minor explosion.
     
  4. indo

    indo Feed me a stray cat
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    Think about the equiv. and 1/2 equiv. points in terms of what species of the biprotic acid are left.

    1. H2A + H2O -> HA- + H3O
    At the 1/2 point [H2A]=[HA-]
    At the 1st eq point the solution is all HA- and you can use the pKa2 to find the pH but don't forget the change in volume when doing the calculations.

    2. HA- + H2O -> A2- + H3O
    Same thing applies here but us the pKb to find the pH at the endpoint.
     

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