Single+Displacement.+Demitri+and+Matt+H.

Single displacement

As decomposition sounds like exactly what it is, so is single displacement. Single displacement is a type of a reaction when a metal reacts with a compound containing a metal, where the single metal in the reaction is more reactive replaces the less reactive metal in the compound.

For example A B C are all different elements, where AC is a compound and B is the lonely metal in the reaction, the element B is more reactive than element C, based on a reactivity chart. B will replace C in the reaction and new compound is formed with a new element formed also.

B + AC -- &gt; C + AB ( this reaction has no relation to the abbreviations of the real elements)

This is a reaction between magnesium (Mg) and hydrochloric acid (HCl) forms magnesium chloride (MgCl2) and hydrogen (H2).

Mg(s) + HCl(aq) → MgCl2(aq) + H2(g)

The Balanced Equation for this reaction is:

Mg + 2HCl --&gt; MgCl2 + H2

Now, with single displacement reactions, a metal or halogen can not replace one that is above it on the Activity Series, which tells us what elements are prone to react more then others.