A single replacement or single displacement reaction is a reaction in which one substance replaces another.
A + BC → AC + B
The replacement of an ion in solution by a metal higher in the activity series is a special example of this reaction type.
The relative positions of the elements in the activity series provides the driving force for single displacement reactions.
A double replacement reaction is one in which there is an actual exchange of partners between reacting species. This reaction is more common between ionic substances;
