Chemistry

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Known:
Cyanaocetic acid
Ka=3.55*10^-3
ionization equation: HC3H2NO2<==> H^+ + C3H2NO2^-
Unknown: pH of 0.4M of Cyanaocetic acid

I can't figure out how to calculate this. I only knew how to calculate the pH value of an acid with a known Ka, but not in this case.

Also, I want to know the second ionization equation of succinic acid because I need to find the Ka expression of this.
Can someone please help me out. Thanks in advance for helping out.

  • Chemistry -

    If you know how to calculate the pH of solution of a known Ka, then why not this one. It's the same thing. For simplicity, let's call this long molecule just HC.
    HC ==> H^+ + C^-
    Now (H^+)(C^-)/(HC) = Ka.
    Do an ICE chart, calculate (H^+) and pH from there.

    Succinic acid.
    http://en.wikipedia.org/wiki/Succinic_acid

    If we call succinic acid H2Su, then
    H2Su ==> H^+ + HSu^- and
    k1 = ......
    Then
    HSu^- ==> H^+ + Su^=
    an k2 = ,......
    I assume you can take it from there.

  • Chemistry -

    What's an ice chart? I don't think I had learned about that..

  • Chemistry -

    Show me how you do the pH of an acid with a Ka.

  • Chemistry -

    For example,
    Given:
    1.000M of Cyanoacetic acid
    pH value of 2
    HC3H2NO2<==> H^+ + C3H2NO2^-
    Unknown: Ka
    pH=-LOG[H^+]
    [H^+]=10^(-2)
    [H^+}=0.01
    Ka=(0.01)(0.01)/(1-0.01)
    =1.01*10^-4?
    Is it right?
    Actually I don't know why [H^+] and [C3H2NO2^-] have the same value, also why [HC3H2NO2] equals initial concentration minus [H^+]?
    Thanks alot

  • Chemistry -

    I think I said something wrong.. I mean I know how to calculate the Ka with a known pH value...sorry..

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