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Heat of formation problem!

  1. Nov 12, 2009 #1
    I'm having trouble with this particular Heat of Formation problem.

    One mole of CH3COCH3 produces -1788.9 kJ of heat when burnt.

    Delta Hf (H2O liquid) = -285.5 kJ
    Delta Hf (CO2 gas) = -393.5 kJ

    Find the heat of formation (Delta Hf) of acetone

    [Answer = -248.1 kJ/mol]


    Solution: (what I have so far)

    3C(s) + 3H2(g) + 1/2 O2(g) ==> C3H6O(g)

    C3H6O(g) + 4 O2(g) ==> 3 CO2(g) + 3 H2O(l) DeltaHf = -1788.9 kJ/mol

    H2(g) + 1/2 O2(g) ==> H2O(l) DeltaHf = -285.5 kJ/mol
    C(s) + O2 (g) ==> CO2(g) DeltaHf = -393.5 kJ/mol

    Not sure what to do after that

  2. jcsd
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