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Homework Help: Naming in hemistry

  1. Feb 17, 2008 #1
    Hi I have a lame question about the naming of chemicals . If we get a combination of 2 chemicals like CO2 why is the C in the first place ? Why isn’t CO2 named O2C ? H2O is another example why not OH2 ? what determines the proper naming of chemicals thanks for the futer answers.
  2. jcsd
  3. Feb 17, 2008 #2
    I'm not a chemist but just thinking about all of the chemical formulas I'm familiar with it seems like they're in alphabetical order.

    The alphabet of which language, I couldn't tell you. I would've thought Latin or Greek or something like that.
  4. Feb 17, 2008 #3
    I believe that the convention of simple molecules such as CO2 and H2O are based on the "core atom" or the one with the lowest electro negativity.

    eg in CO2 the electronegativity of C is = 2.5
    O is = 3.5
  5. Feb 17, 2008 #4
    It's a periodic Trend for the more metallic element to be placed first.

    Or, the further to the left it is.

    It's always NaCl



    Whatever, that is a the basic rule, there are one or two exceptions such at Methan CH4, but that is simply because there are 4 hydrogens, but as a simple rule it seems to work well.
  6. Feb 18, 2008 #5
    O bump

    I never asked a chemist this question maybe one will eventually come here. We have some theories here maybe somebody explain it and be a teacher or phd or professor or something ?
  7. Feb 18, 2008 #6


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    The electropositive constituent (cation) should always be placed first. In the case of binary compounds between nonmetals, the constituent that should be placed first is the one which appears earlier in the sequence: Rn, Xe, Kr, B, Si, C, Sb, As, P, N, H, Te, Se, S, At, I, Br, Cl, O, F. The latter is in accordance with established practice.
  8. Mar 2, 2008 #7
    What chemisttree said holds for most all simple molecules you could write a formula for. As they get more complicated, especially with organic ones, there's an extensive hierarchy of what goes first, how atoms are grouped together, and what name the compound has by IUPAC standards.

    Which can get *really* complicated once you get deep into organic molecules, to the point where you have a method where you assign points to each atom in a molecule to decide whether the molecule has a 'clockwise' or 'anti-clockwise' configuration....
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