Science, Tech, Math › Science Single Displacement Reaction in Chemistry Overview of a Single Displacement or Substitution Reaction Share Flipboard Email Print In a single displacement or substitution reaction, one element replaces another. Don Farrall, Getty Images Science Chemistry Basics Chemical Laws 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 February 08, 2020 A single displacement reaction or substitution reaction is a common and important type of chemical reaction. A substitution or single displacement reaction is characterized by one element being displaced from a compound by another element.A + BC → AC + B A single displacement reaction is a specific type of oxidation-reduction reaction. An element or ion is replaced by another in a compound. Single Displacement Reaction Examples An example of a substitution reaction occurs when zinc combines with hydrochloric acid. The zinc replaces the hydrogen:Zn + 2 HCl → ZnCl2 + H2 Here is another example of a single displacement reaction: 3 AgNO3 (aq) + Al (s) → Al(NO3)3 (aq) + 3 Ag (s) How to Recognize a Substitution Reaction You can recognize this type of reaction by looking for a trade between one cation or anion in a compound with a pure substance in the reactants side of the equation, forming a new compound in the products side of the reaction. If, however, two compounds appear to "trade partners", then you're looking at a double displacement reaction rather than a single displacement. Sources Brown, T.L.; LeMay, H.E.; Burston, B.E. (2017). Chemistry: The Central Science (14th ed.). Pearson. ISBN:9780134414232.