Science, Tech, Math › Science Condensation Reaction Definition in Chemistry What Is a Condensation Reaction? Share Flipboard Email Print Condensation reactions in ribosomes are responsible for amino acid biosynthesis. Stocktrek Images / Getty Images Science Chemistry Chemical Laws Basics Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids 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 August 06, 2018 A condensation reaction is a chemical reaction between two compounds where one of the products is water, ethanol, acetic acid, hydrogen sulfide, or ammonia. A condensation reaction is also known as a dehydration reaction. This type of reaction forms an addition product and water in the presence of a catalyst or under acidic or basic conditions. The opposite of a condensation reaction is a hydrolysis reaction. Condensation Reaction Examples Reactions that produce acid anhydrides are condensation reactions. For example: acetic acid (CH3COOH) forms acetic anhydride ((CH3CO)2O) and water by the condensation reaction2 CH3COOH → (CH3CO)2O + H2OCondensation reactions are also involved in the production of many polymers. In organisms, biosynthesis reactions form peptide bonds between amino acids and are involved in fatty acid formation. Examples of named condensation reactions include aldol condensation, Dieckman condensation, Clasien condensation, and Knoevenagel condensation reactions. Sources Bruckner, Reinhard (2002). Advanced Organic Chemistry (First ed.). San Diego, California: Harcourt Academic Press. pp. 414–427. ISBN 0-12-138110-2."Condensation Reaction". IUPAC Copendium of Chemical Terminology (Gold Book). IUPAC.Voet, Donald; Voet, Judith; Pratt, Chriss (2008). Fundamentals of Biochemistry. Hoboken, NJ: John Wiley & Sons, Inc. p. 88. ISBN 978-0470-12930-2.