How Many Types of Chemical Reactions Are There?

Ways of Classifying Chemical Reactions

Not all chemical reactions produce visible change, but bubbles, color, or temperature changes are common. It's a good idea to memorize the main types of chemical reactions.
Not all chemical reactions produce visible change, but bubbles, color, or temperature changes are common. It's a good idea to memorize the main types of chemical reactions. Trish Gant / Getty Images

There is more than one way to classify chemical reactions, so you may be asked to name the 4, 5, or 6 main types of chemical reactions. Here is a look at the main types of chemical reactions, with links to detailed information about the different types.

When you get right down to it, there are millions of known chemical reactions. As an organic chemist or chemical engineer, you might need to know the details about a very specific type of chemical reaction, but most reactions can be grouped into just a few categories.

The problem is determining how many categories this is. Typically, chemical reactions are grouped according to the main 4 types of reaction, 5 types of reactions, or 6 types of reactions. Here is the usual classification.

4 Main Types of Chemical Reactions

The four main types of chemical reactions are fairly clear-cut, however, there are different names for the reaction categories. It's a good idea to become familiar with the various names so that you can identify a reaction and communicate with people who may have learned it under a different name.

  1. Synthesis reaction (also known as a direct combination reaction)
    In this reaction, reactants combine to form a more complex product. Often there are two or more reactants with only a single product. The general reaction takes the form:
    A + B → AB

     

  2. Decomposition reaction (sometimes called an analysis reaction)
    In this kind of reaction, a molecule breaks into two or more smaller pieces. It's common to have one reactant and multiple products. The general chemical reaction is:
    AB → A + B

     

  1. Single displacement reaction (also called a single replacement reaction or substitution reaction)
    In this type of chemical reaction, one reactant ion changes place with another. The general form of the reaction is:
    A + BC → B + AC

     

  2. Double displacement reaction (also called a double replacement reaction or metathesis reaction)
    In this type of reaction, both cations and anions exchange places, according to the general reaction:
    AB + CD → AD + CB

    5 Main Types of Chemical Reactions

    You simply add one more category: the combustion reaction. The alternate names listed above still apply.

    1. synthesis reaction
    2. decomposition reaction
    3. single displacement reaction
    4. double displacement reaction
    5. combustion reaction
      A general form of a combustion reaction is:
      hydrocarbon + oxygen → carbon dioxide + water

    6 Main Types of Chemical Reactions

    The sixth type of chemical reaction is an acid-base reaction.

    1. synthesis reaction
    2. decomposition reaction
    3. single displacement reaction
    4. double displacement reaction
    5. combustion reaction
    6. acid-base reaction

    Other Major Categories

    Other main categories of chemical reactions include oxidation-reduction (redox) reactions, isomerization reactions, and hydrolysis reactions.

    Can a Reaction Be More Than One Type?

    As you start adding more and more types of chemical reactions, you'll notice a reaction may fit into multiple categories. For example, a reaction may be both an acid-base reaction and a double displacement reaction.

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    Your Citation
    Helmenstine, Anne Marie, Ph.D. "How Many Types of Chemical Reactions Are There?" ThoughtCo, Mar. 8, 2018, thoughtco.com/number-of-chemical-reaction-types-604041. Helmenstine, Anne Marie, Ph.D. (2018, March 8). How Many Types of Chemical Reactions Are There? Retrieved from https://www.thoughtco.com/number-of-chemical-reaction-types-604041 Helmenstine, Anne Marie, Ph.D. "How Many Types of Chemical Reactions Are There?" ThoughtCo. https://www.thoughtco.com/number-of-chemical-reaction-types-604041 (accessed May 27, 2018).