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Emperical/Molecular Formula

  1. Aug 12, 2004 #1
    I was just wondering how would i go about finding the emperical formula for an nickel or dime. I am not about to go and do this but i was just wondering what would be the steps. Would i have to know what it is composed of first and then find out the precentages of each element in the nickel or dime, or there some other way.

  2. jcsd
  3. Aug 13, 2004 #2
    I'm pretty sure you could just send out a sample of the nickel or dime for elemental analysis, and you will be able to determine the formula when you get your results back.
  4. Aug 13, 2004 #3


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    First of all, the nickel or dime is not a molecular solid, so it's constituent elements will not be in some simple whole number ratio. I'm only saying this because of your use of 'empirical formula'.

    The composition of a nickel or dime is not too hard to determine by spectroscopic analysis. XRD (X-Ray Diffraction), XRF (X-Ray Fluorescence), SIMS (Secondary Ion Mass Spectrometry), and NMR are some of the methods used for elemental analysis.
  5. Aug 13, 2004 #4
    You need to ask an analytical chemist for help.
  6. Aug 15, 2004 #5
    To find the empirical formula of some molecule, you would need the percent composition (by mass) of the elements that make up that molecule. To figure out the molecular formula, you would need all that plus the molar mass of the sample. In you case this cant be done because a nickel or dime are made of elements, not molecules.
  7. Aug 15, 2004 #6
    In this case it can't be done because the substance isn't pure, it's a composition of different things. It can be 90% Ni, 5% Zn, 5% whatever. Or it can be 87% Ni...and so on. This does not imply that the nickel itself is a pure substance. To use the empirical formula would imply that NiZn3Al2 (for example) would be consistently found throughout the nickel or dime. This is not the case. The interior of the dime might be Ni, the outside might be Zn, etc. Or maybe the inside is an alloy or something. In either case the ENITRE dime is NOT made of one particular pure substance.
  8. Aug 20, 2004 #7


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    Composition of nickel or dime


    Your query is a daily concern of an analytical chemist, I think. The first step should be a solubilization/or digestion step (of pre-weighed sample ) with very strong acidic mixtures such as HNO3, HCl, H2SO4, and HClO4, etc. The resultant solution will contain all of the inorganic substances in it; the organic ones (if present) should be treated with an alternative way such as solid-liquid extraction, soxhlet extraction, and so on.

    The acidic solution is diluted to a 100-fold of the original sample, and analyzed by atomic absorption spectrometry. This method will give quantitative results such as ppm, ppb, etc. With this data, you can calculate the first concentration in the first solution; and then calculate the overall ionic content of the sample analyzed.

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