Substitution Reaction Definition

What Is a Substitution Reaction in Chemistry?

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A substitution reaction is a type of chemical reaction where an atom or functional group of a molecule is replaced by another atom or functional group.

A substitution reaction is also called a single displacement reaction, single replacement reaction, or single substitution reaction.

Examples: CH3Cl reacted with a hydroxy ion (OH-) will produce CH3OH and chlorine. This substitution reaction replaces the chlorine atom on the original molecule with the hydroxy ion.


  • Imyanitov, Naum S. (1993). "Is This Reaction a Substitution, Oxidation-Reduction, or Transfer?". J. Chem. Educ. 70 (1): 14–16. doi:10.1021/ed070p14
  • March, Jerry (1985). Advanced Organic Chemistry: Reactions, Mechanisms, and Structure (3rd ed.). New York: Wiley. ISBN 0-471-85472-7.
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Helmenstine, Anne Marie, Ph.D. "Substitution Reaction Definition." ThoughtCo, Aug. 28, 2020, Helmenstine, Anne Marie, Ph.D. (2020, August 28). Substitution Reaction Definition. Retrieved from Helmenstine, Anne Marie, Ph.D. "Substitution Reaction Definition." ThoughtCo. (accessed January 27, 2023).