Organic nomenclature is usually taught as part of any introduction to organic chemistry. To help introduce students to organic nomenclature in a way that clearly summarizes the patterns that exist, a paper tool for naming hydrocarbons was developed.
This classroom activity covers the IUPAC nomenclature system for saturated and unsaturated hydrocarbons. Using the paper tool developed, students write the names of the first ten unbranched alkanes, simple branched-chained alkanes, and simple unsaturated hydrocarbons with one or two double or triple bonds.
Organic nomenclature is usually taught as part of any introduction to organic chemistry and is often covered to some extent in general chemistry courses. The details taught often vary, but most students are introduced to simple hydrocarbons first, followed by other functional groups. I have primarily taught organic nomenclature to Allied Health students in an introductory general, organic, and biochemistry course at a community college. We have recently simplified our teaching of organic nomenclature, but historically, it has been covered extensively in this particular course at our college. The IUPAC rules for naming are often covered quickly, and students sometimes become overwhelmed by the details and struggle to recognize the simple patterns in the naming system. To help introduce students to organic nomenclature in a way that clearly summarizes the patterns that exist, I designed a series of paper tools for naming hydrocarbons, major functional groups, and common names of certain classes of organic compounds.
These paper tools are easy to print and distribute to every student each semester and students can easily put them in their folder or book. Both PDF and Word documents are available to allow for easy modifications to be made to match the types of compounds covered in a particular course. While the details like numbering, branching, or cis/trans isomerism are not shown in this paper tool, it gives a starting place for students to see the general patterns of the IUPAC naming system. This has been written for an introduction in one class session. I usually first introduce simple alkanes, and then introduce this tool when I start expanding to cover alkyl substituents and unsaturated hydrocarbons.
A majority of the students surveyed after using these paper tools indicated the tools helped them understand relationships between structures and names. While most students indicated that they find them helpful when they first begin naming organic molecules, some students continue to use these tools as a reference while studying.
Following an introduction, a game (Crute, T. D. "Classroom Nomenclature Games—BINGO." J. Chem. Ed. 2000, 77, 481-2) could be used to help students recognize the various parts of structures to help students construct the names of more complex hydrocarbons.
The paper tools can be assembled according to the photo in Figure 1 (leftmost image below) with one staple in the center (location marked in red on the image) to hold it together while still allowing each side to slide easily.
To use this paper tool, first slide the left side insert to show the correct number of carbons in the continuous chain just below the "number of carbons." In Figure 2 (middle image above), the example is highlighted in blue as "four" carbons. Slide the right side to show the correct description of the bonds/features present just below "Bonds/Features." In Figure 2, the example includes one double bond (highlighted in blue). The name of the indicated chain will be show just above "PARENT NAME." The example in Figure 2 has the "parent name" "butene". In Figure 3 (rightmost image above), the example shows a chain with "6" carbon atoms and a "triple bond." The "parent name" "hexyne" is highlighted in blue in this example.
A sample page of structures is provided to practice using the paper tool to name a series of hydrocarbons with increasing complexity.
Print one copy of both pages of the "Hydrocarbon Paper Tool" for every two students. For best results, choose "actual size" when printing on medium cardstock. These can be separated into single tools in advance using a paper trimmer, or students can cut them with scissors. They may need to be trimmed slightly depending on the printing to make sure they line up correctly.
Melanie J. Harvey, Professor of Chemistry, Johnson County Community College