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Chemical Compound Formula

  1. Feb 20, 2010 #1
    1. The problem statement, all variables and given/known data

    35.0mg of C-H-N (the unknown is the empirical formula) combusts to produce 33.5mg CO2 + 41.4mg H2O

    2. Relevant equations
    I'm confused by the fact the product does not include N so I'm unsure how to figure for it.

    3. The attempt at a solution
    Using all the information stoichometrically I have surmised 2 mols of O, 6 mols of H, 1 mol of C.
    I used the same type of equations for each ie:
    .0335g CO2 (1mol CO2/1mol C 44.01g) * (2mol O/ 1 Mol CO2) = .001522

    Oncea again I'm stumped on how to figure the N....

    Any help appreciatted!

  2. jcsd
  3. Feb 20, 2010 #2
    I didn't do the calculation but once you figure out how many mols of C and H you convert back to mass then add them together and find the difference from the total giving you the mass of N. Then you set up the proportions to find their relative amounts for the empirical formula (I believe you should be using the mols instead of the mass for the proportions).
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