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How do I learn to make isomers for a compound?

  1. Feb 22, 2016 #1
    I get so confused when it comes to making isomers for a compound like propanol,di ethyl ketone and those which has double and triple bonds.
    It seems I can make an isomer by changing the position of double bonds too.
    Isn't there any easy way to do it? Also When I come up with 4 isomers for a compound,internet already contains 8 of them and then I wonder why I didn't get the idea to arrange them into four more by changing the positions further more.It would look as if the 4 isomers I came up with are the only ones available until I get to refer the websites.
    So is there any way to check whether the number of isomers I came up with are correct ones?
  2. jcsd
  3. Feb 22, 2016 #2


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    Short answer? "No." Slightly longer answer? You are talking isomers; the number of configurations/conformations/congeners/xxxxxxxs expands rapidly; get beyond a dozen atoms and very few people are able to guarantee a complete list.
  4. Feb 22, 2016 #3


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    Whether it counts as an easy method depends on what you call easy. It is not that difficult to design a recurrent algorithm that will generate all possible isomers of a compound with a given formula - choose one atom as a starting one. For the incomplete molecule for each bond sticking out try to add another atom from the formula till you run out of atoms.

    While this is guaranteed to generate all possible isomers, there are two problems - one, many of the generated formulas will repeat, second, many of them are chemically impossible.
  5. Feb 22, 2016 #4
    Can you just elaborate more on this,please?
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