This molecule is ethane (example 1) [LINK URL:

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1 Although there are many aspects of a molecule that contribute to it s nomenclature (process of organized naming), we are going to start out with simple carbon chains. To clarify, a simple carbon chain is a number of carbons with single bonds to 1-2 other carbons, and the remaining 2-3 available bonding areas are bonded to hydrogen. Here are two examples below: This molecule is ethane (example 1) [LINK URL: This molecule is propane (example 2) [LINK URL: These two molecules are very similar, being as they consist of only carbon and hydrogen atoms. In organic chemistry, these simple carbon chains are usually called alkanes. For more information about alkanes and other functional groups, refer to the 'Functional Groups' subgroup of Organic Chemistry. Both our example molecules are simple carbon chains (alkanes), but they are different because they have different amounts of carbons. Propane has a longer carbon chain than ethane, because it has three carbons bonded together in a chain compared to ethane s two carbon chain. For simple carbon chains, the length of the carbon chain is what determines the name of the molecule. Refer to the table below: Number of Carbons Prefix 1 meth- 2 eth- 3 prop- 4 but- 5 pent- 6 hex- 7 hept- 8 oct- 9 non- 10 dec- 11 undec- 12 dodec- 1 / 5

2 13 tridec- 14 tetradec- 15 pentadec- 20 eicos- The prefixes in the table are how you begin the name of the molecule (the prefix). If the molecule you are dealing with is an alkane, the suffix you would attach to the prefix would be ane. Referring back to our first example, ethane is named so because it has a two carbon chain (eth-) and is an alkane (-ane). Put the prefix and suffix together and we named our molecule ethane! History Explore the discoverer's biography, including general facts about his life and anecdotes regarding how he made this particular discovery. Also see other significant scientific discoveries built largely on this concept and other real-world applications in history that may not still be relevant. Discoverer/Developer Two people, Archibald Scott Couper and August Kekule, simultaneously and independently, concluded that organic molecules consisted of a structure, and that this structure has a connection of carbons. 3 The discovery of chemical structure created an explosive burst in organic chemistry research at the time (approximately 1860 onward), because it provided a more tangible method to think about and teach chemistry. August Kekule was born September 7, In college he originally wanted to be an architect, but was persuaded to study chemistry after hearing the teachings of Justus Liebig. In 1856, Kekule moved to University of Heidelberg as a lecturer/researcher. He published two papers (one in 1857 and one in 1858) about his breakthrough; simple organic chemical molecules have a carbon-chain structure, in which other atoms can join the carbons on the chain. 1 Kekule was influenced by many chemists, but one of the most prominent would be Freidrich Wohler, who through inorganic molecules synthesized the organic molecule urea. 2 Archibald Scott Couper published a paper in 1858 as well about the chemical structure of molecules and how they interact with other molecules. 3 However, Kekule got most of the credit for the discovery of chemical structure. Couper fell into a case of mental and physical illness, living in retirement for the rest of his days. 3 2 / 5

3 Concept Definition Study the primary definition of this concept, broken into general, basic, and advanced English definitions. Also see the mathematical definition and any requisite background information, such as conditions or previous definitions. Basic Chain length can be defined as the amount of carbons bonded together. Advanced Chain length can be defined as the largest amount of carbons bonded to 1-2 other carbons, with the remaining bonds bonded to hydrogen. Vocabulary Learn important vocabulary for this concept, including words that might appear in assessments (tests, quizzes, homework, etc.) that indicate the use of this concept. Important Vocabulary Term Context Alkanes A group in organic chemistry whose functional group consits of carbons Nomenclature The process of organized naming for molecules. Prefix The beginning of the name of a molecule. In alkanes, this is determined b Suffix The ending of the name of a molecule. This is determined by the function Videos Browse relevant videos from the Journal of Chemical Education's (JCE) Chemistry Comes Alive! library and other video sources. Molecular Models of Methane A molecular model of methane is shown and its shadow is used to draw its structure on paper. Ethane Ethane's molecular structure. Organic Chain Length Naming Song 3 / 5

4 chain length nomenclature song Study Aides Uncover helpful study tools, such as a mnemonic device or alternative ways to master the concept. Study Aides A great idea to demonstrate chain length is to build simple carbon chains. If you have modeling set/s this is great, but you can also do it with Styrofoam balls and pipe cleaners. Feel free to get creative by making simple carbon chains with anything else you can think of, like toothpicks and candy! Sample Problems Explore sample problems from the JCE QBank and other sources. Sample Problems Works Cited Review the works cited to write the researched parts of this page, such as the discover's biographical information and other areas. Works Cited [URL: [URL: 4 / 5

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