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Stoichiometric ratio calculation

  1. Oct 18, 2013 #1
    Dear all,

    I am trying to synthesis a compound as given the paper below. Can someone help me of how to calculate the stoichiometric ratio and amount of each compound (i.e. Nd pieces, As, Fe, Fe2O3, FeF3 powders) required to prepare the same compound as in that paper. Especially I don’t know the balanced equation.

    Preparation of superconducting compound is given in the following paper:
    Doi: 10.1209/0295-5075/82/57002
    The superconducting compound is Nd[O0.89F0.11]FeAs.
    It is mentioned in that paper as follows:
    Nd pieces, As, Fe, Fe2O3,FeF3 powders (the purities of all starting chemicals are better than 99.99%) were mixed together according to the nominal stoichiometric ratio of Nd[O0.89F0.11]FeAs, then ground thoroughly and pressed into small pellets.

    thanks and regards, Rajini.
     
  2. jcsd
  3. Oct 18, 2013 #2

    Borek

    User Avatar

    Staff: Mentor

    You can't balance a reaction in a standard way, when the compound has non-integer coefficients. But the stoichiometry still holds - 1 mole of Nd[O0.89F0.11]FeAs contains 1 mole of Nd, 1 mole of Fe, 1 mole of As, 0.89 moles of O and 0.11 moles of F. Assume you are going to make 1 mole. Start calculating how much Fe2O3 you need to get correct amount of oxygen, then how much FeF3 for fluorides, then check how much Fe you already have and calculate how much Fe to add to make its total up to 1 mole. The rest should be obvious.
     
  4. Oct 18, 2013 #3
    solved

    Hello Borek,

    I got your suggestion:
    Is the following correct?
    Nd + As + 0.3699Fe + 0.2967 Fe2O3 + 0.0367 FeF3 -> Nd[O0.89F0.11]FeAs.
    I think I can now calculate grams of each compound reruired to prepare..
    Regards, Rajini.
     
  5. Oct 18, 2013 #4

    Borek

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    Staff: Mentor

    Looks OK to me.
     
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