IUPAC NamingNaming an organic molecule in five steps.ChemistryThe systematic procedure.1Find the longest chain containing the groupNot necessarily drawn as a straight line.2Number from the end nearest the groupFunctional group gets the lowest possible number.3Identify substituentsMethyl, ethyl, chloro, and so on.4Order alphabeticallyIgnore di-, tri- when alphabetising.5AssembleSubstituents, then stem, then suffix.EXAMPLECH₃CH(CH₃)CH₂CH₂OHLongest chain: 4 carbons — butan-1-olMethyl on carbon 33-methylbutan-1-olNumber to give the functional group the lowest locant, even if that givessubstituents higher numbers.IUPAC Naminglearnposters.com
IUPAC Naming — printable physical science wall chart from LearnPosters. Free vector PDF, US Letter and A4.

IUPAC Naming, step by step

The systematic procedure.

  1. Find the longest chain containing the groupNot necessarily drawn as a straight line.
  2. Number from the end nearest the groupFunctional group gets the lowest possible number.
  3. Identify substituentsMethyl, ethyl, chloro, and so on.
  4. Order alphabeticallyIgnore di-, tri- when alphabetising.
  5. AssembleSubstituents, then stem, then suffix.

Example

  • CH₃CH(CH₃)CH₂CH₂OH
  • Longest chain: 4 carbons — butan-1-ol
  • Methyl on carbon 3
  • 3-methylbutan-1-ol

Number to give the functional group the lowest locant, even if that gives substituents higher numbers.

Questions about the IUPAC Naming poster

What’s on the IUPAC Naming poster?
5 numbered steps, with a full worked run-through. The systematic procedure. Find the longest chain containing the group — Not necessarily drawn as a straight line.; Number from the end nearest the group — Functional group gets the lowest possible num…; Identify substituents — Methyl, ethyl, chloro, and so on.; Order alphabetically — Ignore di-, tri- when alphabetising.; Assemble — Substituents, then stem, then suffix.. Number to give the functional group the lowest locant, even if that gives substituents higher numbers.
Who is the IUPAC Naming poster for?
IUPAC Naming belongs to the Chemistry section rather than to a school year, because physical science is not something one grade owns. Anyone learning organic can pin it up — a beginner, a student mid-course, or someone revising years later.
When should you use the IUPAC Naming poster?
Longest chain, lowest numbers, alphabetical order. That is nearly all of it. A wall chart earns its place by being glanceable from where the work is happening, so IUPAC Naming belongs on the wall where that physical science work actually happens, within glancing distance, rather than filed away.
What other posters go with IUPAC Naming?
Functional Groups, Alcohols and Alkanes sit alongside IUPAC Naming in the Chemistry section. Printed together they make a wall rather than a single sheet, which is how a reference set actually gets used.Functional GroupsAlcoholsAlkanes
Is the IUPAC Naming poster free to download and print?
Yes. IUPAC Naming downloads as a free PDF with no account, no email and no watermark, like everything else in the Chemistry section. Print as many copies as you like for a home, a classroom, a library or a tutoring group; reselling the file is the only thing the licence rules out.Read the licence
What size does the IUPAC Naming poster print at?
IUPAC Naming is a vector PDF laid out for US Letter, and prints on A4 with Fit to page — the same file, no separate download. Because every mark on it is drawn rather than photographed, it stays sharp enlarged to A3, A2 or A1 at a copy shop. Colour carries emphasis only, so a greyscale print of IUPAC Naming loses nothing.Printing guide

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