Science, Tech, Math › Science Odor of Violets Chemistry Demonstration Share Flipboard Email Print Ursula Alter / Getty Images Science Chemistry Activities for Kids Basics Chemical Laws Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. our editorial process Facebook Facebook Twitter Twitter Anne Marie Helmenstine, Ph.D. Updated November 18, 2019 In this chemistry magic trick, you'll produce the odor of violets by mixing two common chemicals. This demonstration is also known as the flower shop magic trick. Materials Sodium carbonate and castor oil are sold at many stores. Sodium carbonate is used in cooking and as a water softener. Castor oil usually is sold in the pharmacy section. Sodium carbonateCastor oil Perform the Trick This is a terrific chemistry demonstration because the materials are common and inexpensive and it's extremely quick and easy to perform: In a dry test tube or small beaker, add a scoop of sodium carbonate and 3 drops of castor oil.Heat the container in a burner flame or on a hot plate until a cloud of white vapor rises from the chemicals.Walk around the room with the glassware to allow the fragrance to dissipate. The odor of violets is evident. How It Works When sodium carbonate and castor oil are heated together, one of the products is ionone. Although it is a simple demonstration, this is a fairly complicated reaction, in which citral and acetone with calcium oxide catalyze an aldol condensation followed by a rearrangement reaction. A mixture of alpha and beta-ionone is responsible for the characteristic odor of violets. Beta ionone is a component of the fragrance responsible for the scent of roses, too. Natural or synthetic ionone is used in many perfumes and flavorings. In flowers, ionones derive from the degradation of carotenoids, which are pigment molecules. An interesting property of violets is that they are responsible for another type of chemical magic. Violets temporarily steal your sense of smell! Initially, ionone binds to scent receptors and stimulates them, so you smell the odor of violets. Then, for a few moments, the receptors are unable to receive a further stimulus. You lose awareness of the fragrance, only to regain it when it registers as a new smell. Whether you like the scent of violets or not, it's a scent that can't become overpowering or fade with time.