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STEM Education Poetry

Alkane Knowledge

“Naming a molecule:
Precise endeavor that
Draws on organic skills
Nuanced and vast.
Start with the carbon chains;
Look for the longest (and
So on, and so on, with
Concepts from class).”

The 5 October 2020 Twitter poem addressed a common objective from introductory and organic chemistry coursework: learning how to name a molecule.  

“Naming a molecule: /
Precise endeavor that /
Draws on organic skills /
Nuanced and vast.”
A few of these posts have already addressed some of the intricacies of chemical nomenclature.  Chemists have developed systematic rules for naming compounds: an early consideration is whether a compound is inorganic or organic, as each classification requires its own precise set of rules.  These rules are managed by the International Union of Pure and Applied Chemistry, or IUPAC.  Organic compounds are often interchangeably called molecules.  To name a molecule thus requires “organic skills [that are] nuanced and vast.”

“Start with the carbon chains; /
Look for the longest (and /
So on, and so on, with /
Concepts from class).”
In an acyclic hydrocarbon molecule, the first rule of naming is to identify the longest carbon chain.  This will inherently give the root word of the name; for instance, a saturated hydrocarbon chain containing six carbons all bonded to one another in a line is called hexane.  

The dismissive “and so on, and so on” mention in the poem omits much follow-up information.  The rules of naming then involve considering what side chains are bonded to that longest chain, whether any functional groups are involved, whether any double or triple bonds are present, and many other considerations.   It requires much practice to use nomenclature “concepts from class” in any efficient way.  

The title here confines our analysis to the very simplest cases: hydrocarbon compounds where each carbon atom is saturated, or bonded to four other atoms; such compounds are called alkanes.  Moreover, the title allows a play on words with “arcane knowledge,” a description that can certainly seem apt for nomenclature!