What is the difference between a decomposition reaction and a replacement reaction?

Apr 12, 2014

A decomposition reaction is one where a compound is broken down into its constituent chemical species:

For example:

$2 N a C l \to 2 N {a}^{+} + C {l}_{2}^{-}$

The $N a C l$ was broken down into the constituents $N {a}^{+}$ and $C {l}_{2}^{-}$

--(side note: the $C l$ is diatomic that explains the $2$)

There are two types of replacement reactions, observe the differences:

Single Replacement: $A B + C \to A C + B$

Double Replacement: $A B + C D \to A D + C B$