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Chemistry

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What is initial concentration of a sodium acetate if the pH (at epuilibrium) is measured to be 9.30?

  • Chemistry -

    ............Ac^- + HOH ==> HAc + OH^-
    initial.....y........0.......0.....0
    change.....-x...............x......x
    equil......y-x...............x......x
    y = initial concn Ac^- which is our unknown.
    pH = 9.30; convert to H^+ which is 5.01E-10
    Therefore OH^- = Kw/(H^+) = 1E-14/5E-10 = 2E-5 but you should be more accurate.
    Kb for acetate = (Kw/Ka for acetic acid) = (HAc)(OH^-)/(Ac^-)
    (Kw/Ka) = (x)(x)/(y-x)
    For x you insert 2E-5; solve for y.

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