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Homework Help: Mass-Mole conversion

  1. Jul 3, 2009 #1
    1. The problem statement, all variables and given/known data
    Show that 1kg of CaF2 equals 13 mol.

    2. Relevant equations
    Molar mass CaF2 = 78.074g/mol

    3. The attempt at a solution
    I can take 78.074g/mol CaF2 * 13 mol = 1014.962 g CaF2
    But I can't do this equation backwards, I'm missing a step. I would think if I'm converting g/mol to mol, I would divide by how many grams I have (1000 in this case), but 78.074g/mol CaF2 / 1000g [tex]\neq[/tex] ~13mol.

    Edit: I'm dumb. 1000/78.074 = ~13mol. Kill me now.
    Last edited: Jul 3, 2009
  2. jcsd
  3. Jul 3, 2009 #2


    User Avatar

    Staff: Mentor

    You got it correctly on your own, there is still hope :wink:

    Pay attention to units:

    [tex]\frac {78 \frac g {mol}} {1000 g} = 0.078 \frac 1 {mol}[/tex]

    - and it is obvious what went wrong.
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