Clarifying organic nomenclature

Naming organic chemical compounds can appear to be an impenetrable challenge for chemistry students. While IUPAC nomenclature of organic molecules is a systematic process, how the rules are applied can be confusing. Even very simple structures can be assigned multiple, and often very different, names (for example, dichloromethane/methylene chloride). Knowing which is formally correct requires understanding the nuances of priority assignment. For students who are getting to grips with how atoms can bond together and the properties of functional groups, the additional complexity of how we name those arrangements can be overwhelming.

If you want to help your students with naming organic compounds, the Organic Nomenclature website has clear guides to assigning names and lets students jump right into quizzes to test their knowledge.

The nomenclature rules section of this site focuses on the principles of naming – how to build up names and prioritise functional groups. This is a very structured and coherent approach that doesn’t bombard the student with exhaustive lists of functional groups or the intricacies of stereochemical assignment. Instead, these topics are explained separately in appendices.

Of course, the best way to develop confidence in naming compounds is to practice on real examples. The key feature of the Organic Nomenclature website is the ability to build and take quizzes so students can practice. These can be taken at one of the three preset levels of difficulty which allows students to practice the basics before moving onto more complex examples, or you can prepare a quiz with specific molecular features.

Each quiz alternates questions between assigning names to a given structure and drawing a structure from a given name.

There is, however, a problem with the quiz format on the site: some of the answers to the questions are wrong. In my testing, one or two questions in each quiz evaluated correct answers as incorrect. When checked, the ‘correct’ answer given by the site is often incorrect in ways that might not be obvious to novice students. Of course, this could be very confusing. So, if you decide to incorporate  quizzes from this website into your own teaching, you should be aware of this and avoid leaving students to work through quizzes on their own with no additional guidance.