• Question: What are the rules when naming compounds?

    Asked by rhooper821 to Ben, Dave, Ed, Sam, Susana on 18 Jun 2013.
    • Photo: Sam Horrell

      Sam Horrell answered on 18 Jun 2013:

      Thats a great question. Back in the old days elements were named by whoever discoverd them. Normally they have some route in Greek, Latin and some times even Norse. Usually based on their appearance or how they interact with other chemicals. Now new element names are decided by the International Union of Pure and Applied Chemistry (IUPAC).

      There are lots of standard ways of naming compounds and they almost always involve greek and latin too.

      Hydrocarbons for example:
      The fist part is normally a greek or latin number like “hex” which means 6. This tells us there are 6 carbon in the molecule.
      This is normally followed by a suffix that tells us something about the molecule. “Ane” for example means the molecule is an alkane so has no double bonds between carbons.
      So hexane would be a 6 carbon molecule with all single bonds between carbons with all other carbons bound to hydrogen.
      This method was also decided by the IUPAC

    • Photo: Susana Teixeira

      Susana Teixeira answered on 19 Jun 2013:

      As Sam mentioned, the internationally accepted rules are set by IUPAC, although very often compounds also get known for their commercial name or some form of abbreviation.
      It’s a bit long to explain here but I will give you an example here and then you can go and watch a fun video at the end.
      Let’s take 2-methyl-2,4-pentanediol, an IUPAC name. It is much better known as MPD, cause us scientists are lazy sometimes… The IUPAC name is saying that:
      – at position 2 of the chain there is a Methyl group (CH3), and we know it is a methyl because the prefix “Meth” tells us there is just one carbon
      – at positions 2 and 4 of the chain there are 2 alcohol groups (OH), that is what “diol” means
      – we know is is a chain of 5 carbons because it is a PENTane
      – we know there are only single bonds in the chain because it is a pentANE.

      So you can probably have a go at drawing the molecule now! If not this extra video will help: http://youtu.be/Y0GeSMAF3cs

    • Photo: David Briggs

      David Briggs answered on 19 Jun 2013:

      Rules for Chemicals are set by IUPAC. But that is boring. Because chemists are boring.

      Rules for naming proteins & genes are much more fun – because basically – THERE AREN’T ANY.

      There are genes in fruit fly that scientists call things like:
      “Indy” (stands for I’m Not Dead Yet – flies with mutations in the Indy gene live twice as long as normal flies),
      “Cheap Date” (increased sensitivity to alcohol) and
      “TinMan” ( the mutant has no heart).

      Biologists are much more fun than Chemists. 😆

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