Zn (s) + CuSO 4 (aq) → Cu (s) + ZnSO 4 (aq)Single displacement reactions are often further classified as redox reactions. (These will be
discussed in more detail in chapter 14 .)
DOUBLE DISPLACEMENT REACTIONS
In double displacement reactions, also called metathesis reactions, elements from two different
compounds displace each other to form two new compounds. For example, when solutions of
calcium chloride and silver nitrate are combined, insoluble silver chloride forms in a solution of
calcium nitrate.
CaCl 2 (aq) + 2AgNO 3 (aq) → Ca(NO 3 ) 2 (aq) + 2AgCl (s)Neutralization reactions are a specific type of double displacements that occur when an acid reacts
with a base to produce a solution of a salt and water. For example, hydrochloric acid and sodium
hydroxide will react to form sodium chloride and water.
HCl (aq) + NaOH (aq) → NaCl (aq) + H 2 O (l)This type of reaction will be discussed further in the chapter on Acids and Bases, chapter 13.
QUICK QUIZ
Match the type of reaction with the lettered description below.1. Synthesis reaction
2. Decomposition reaction
3. Single displacement reaction
4. Double displacement reaction
Elements from two different compounds displace each other to form two new
compounds.