Single Displacement Reactions
Another type of redox reaction is one in which an element replaces or displaces
another from a compound. In these reactions, known as single replacement
reactions, the element which replaces that which is in a compound is always
oxidized. The element being displaced, is always reduced. This is illustrated
by the displacement of hydrogen gas by metallic iron in the example below:
The oxidation of iron is represented by:
Note that the net charge on both sides of the arrow must always be equal to each other.
The reduction of hydrogen is represented by:
Note: In both oxidation and reduction, the net charge of both sides of the arrow must always be equal.
Another example is the replacement of silver by copper.
Note: Copper is oxidized; silver is reduced.