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Homework Help: Formula and Combining Compounds

  1. Mar 19, 2010 #1
    1. The problem statement, all variables and given/known data
    What is the formula and name of the compound by combining Pb2+ and CrO42-

    2. Relevant equations

    3. The attempt at a solution
    I thought it was Pb2(CrO4)2 - Lead Chromate.
    Why is this wrong and how do I correct it?
  2. jcsd
  3. Mar 19, 2010 #2
    When writing ionic compounds, you use the smallest number ratio between the ions; you don't always "switch" the charges. Instead of a 2:2 ratio, use a 1:1 ratio for the formula, PbCrO4.
    The name is wrong because you need to specify the charge of lead since it has a variable charge.
  4. Mar 20, 2010 #3

    Char. Limit

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    Gold Member

    By the way...

    Pb2+[/sub] = Plumbous
    Pb4+[/sub] = Plumbic
  5. Mar 21, 2010 #4
    Is PbCrO4 - Lead II Chromate correct?
  6. Mar 21, 2010 #5


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    Staff: Mentor

    Looks Ok to me, but Eglish nomenclature is not my forte.
  7. Mar 21, 2010 #6

    Char. Limit

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    Gold Member

    That'll work too.

    I just prefer the old system.

    Lead(II) Chromate is good.
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