Double Displacement• 2 compounds are reacted together

and the first part of each compound will switch places • general equation :

WX + YZ WZ + YX

There are three types of double displacement reactions:

• a reaction that forms a solid• a reaction that forms a gas• a reaction that forms water

(neutralization)

A reaction that forms a solid:

• A common observation during a double displacement reaction is the formation of a solid precipitate

• ex. Pb(NO3)2 (aq) + 2KI (aq) PbI2 (s) + 2KNO3 (aq)

Solubility Table

• You have been given a solubility table on the back of your periodic table

• To use your solubility table: – Identify the anion in the top row– Identify the cation in the column below the

chosen anion– If they have a high solubility then a precipitate

will not be formed, if they have a low solubility then a precipitate likely will form.

A reaction that forms a gas:

• Sometimes a double displacement produces a gas rather than a precipitate.

Reactants Products

Acid + compound containing carbonate ion

Ionic compound + water + carbon dioxide

Compound containing ammonium ions + compound containing hydroxide ions

Ionic compound + water + ammonia

A reaction that forms water:

• When a reaction takes place through the combination of an acid and a base which results in the formation of water is called Neutralization

• Neutralization: the process of making a solution neutral (pH = 7) by adding a base to an acidic solution or by adding an acid to a basic solution

Summary of Double DisplacementIf one reactant : If the other reactant: Then the products will

include:

Is an Aqueous Salt Is an Aqueous Salt A Precipitate

Is an Acid Has Carbonate Ions Water and carbon Dioxide

Has Ammonium Ions Has Hydroxide Ions Water and Ammonia

Is an Acid Has hydroxide Ions Water + a Salt

Practice Problems

1) Potassium carbonate and hydrochloric acid2) Ammonium chloride and sodium hydroxide3) Calcium carbonate and acetic acid4) Lithium hydroxide and ammonium bromide5) Sulfuric acid and lithium hydroxide6) Calcium hydroxide and nitric acid

Practice Problems• 1)Potassium carbonate and hydrochloric acid• K2CO3(aq) +2 HCl(aq) 2KCl (aq) + H2O(l) + CO2(g)

• 2) Ammonium chloride and sodium hydroxide• NH4Cl(aq) + NaOH (aq) NaCl (aq) + NH3 (g) + H2O(l)

• 3) Calcium carbonate and acetic acid• CaCO3(s) + 2HCH3COO(aq) Ca(CH3COO)2(aq) + H2O (l) + CO2 (g)

• 4) Lithium hydroxide and ammonium bromide• LiOH(aq) + NH4Br(aq) LiBr(aq) + H2O (l) NH3(g)

• 5) Sulfuric acid and lithium hydroxide• H2SO4(aq) + 2LiOH(aq) Li2SO4(aq) + 2H2O(l)

• 6) Calcium hydroxide and nitric acid• Ca(OH)2(aq) + 2HNO3(aq) Ca(NO3)2 (aq) +2H2O(l)