A single-replacement reaction is a chemical reaction in which one element is substituted for another element in a compound, generating a new element and a new compound as products.
A double-replacement reaction occurs when parts of two ionic compounds are exchanged, making two new compounds. A characteristic of a double-replacement equation is that there are two compounds as reactants and two different compounds as products.
The key difference between single displacement and double displacement reaction is that, in single displacement reactions, one chemical species replaces a part of another chemical species whereas, in double displacement reactions, exchange of two ionic species between two molecules occur.
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