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Homework Help: Solution stoichometry, attempted ANSWER IS WRONG, can anyone fix answer

  1. May 14, 2010 #1
    A 15.0 mL sample of an unknown H3PO4 solution requires 110 mL of 0.120 M KOH to completely react with the H3PO4 according the following reaction.

    H3PO4 + 3KOH --------> 3H20 + K3PO4

    What was the concentration of the unknown H3PO4 solution?

    ______________________________________…

    This SEEMED correct way to start problem, as it turns out this is not how to set up the problem, (attempt at doing the problem) : 15mL converted that to L , got 0.015 L, then multiplied that by .12 moles of the solute KOH divided by 1 Liter of the solution H3PO4, used the mole to mole conversion 3 moles of KOH to every 1 mole of H3PO4 and got the wrong answer. It's supposed to be
    .293 Molarity.

    ??????
     
  2. jcsd
  3. May 14, 2010 #2
    You have to do the three dissociation reactions separately.
     
  4. May 15, 2010 #3

    Borek

    User Avatar

    Staff: Mentor

    15 mL is the volume of acid, not base.

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