The smell of chemistry

This post is from ScIU’s archives. It was originally published by Victoria Kohout in August 2017, and has been lightly edited to reflect current events.

Chocolate chip cookies fresh from the oven. Your grandmother’s perfume. Newly cut grass. Each of the listed descriptions is extremely different but can be linked together by one fundamental thread–smell. Smell or olfaction is an essential sense in everyday life that helps guide what we eat and how we perceive the world around us. It has even been predicted that humans may be able to distinctly discriminate more than one trillion different scents!¹

Although nearly everyone is familiar with the common scents like vinegar or rancid meat, only a handful of people are acquainted with the common chemical names associated with these smells, and even less are able to identify their molecular structure. Acetic acid–vinegar–or (R)-(–)-carvone–spearmint–can sound misleading or even strike fear in those that are not familiar with what they are. Demystifying these names and what these molecules look like could help the general public better understand the chemicals in their everyday lives, and possibly open the door to more in-depth discussions about chemistry. 

There are a variety of popular ways to introduce chemical concepts like smell to a general audience. Chemistry demonstrations are often used to convey chemical topics and capture the imagination with their bright color changes or even small explosions. Many of these demonstrations, however, require specialized spaces and trained individuals to handle the chemicals, and they lack long-term visibility. It is possible to circumvent these limitations by creating a more permanent display such as a museum exhibit. In the past several years, Dr. M. Kevin Brown and Dr. Laura Brown from the IU Department of Chemistry, in collaboration with the WonderLab Museum of Science, Health and Technology in Bloomington undertook this challenge to fashion and implement a brand new interactive chemistry exhibit.²

The exhibit’s goal was to introduce the concept that scents are chemicals and that the molecular structure of these molecules determines biological activity. After selecting a number of common scents that a person could run into in their everyday lives, a two component exhibit was developed to introduce these scents and their chemistry to an audience of all ages, especially focusing on educating young children. The first part of the exhibit was composed of a custom-made station known as “Guess the Scent.” This station permits visitors to smell a scent and then identify it with a puzzle piece. The puzzle piece includes the chemical structure of the scent molecules along with its chemical name and several fun facts about it. Also, at each station, there is an already assembled molecular model for each scent to further help museum visitors conceptualize the scents 3-D shape. The second and final part of the exhibit includes a molecular model station for further fun. Each visitor has the opportunity to build the scent molecules that they just smelled along with a handful of other scent molecules that they may run into on a daily basis.

The “Guess the Scent” and scent molecular structure table is not currently available at the WonderLab Museum, but take some time to understand the smell of chemistry around you!

Edited by Lana Ruck and Karna Desai

¹Bushdid, C., Magnasco, M.O., Vosshall, L.B., & Keller, A. Science. 2014, 343, 1370-72. DOI: 10.1126/science.1249168
² Brown, M.K., Brown, L.C., Jepson-Innes, K., & Stone, J. J.Chem.Ed. 2017, 94, 251-255.

Photo references:
Thank you, Dr. Laura Brown, for the wonderful WonderLab photos of the display.
Vinegar: “Creative Commons Eight year old Aceto balsamico di Modena” by Rainer Zenz licensed under CC BY-SA 3.0.