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(NO 3 ) 2 (aq) + 2KI (aq)  PbI 2 (s) + 2KNO 3 (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. ReactantsProducts 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: W hen 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 Displacement If one reactant :If the other reactant:Then the products will include: Is an Aqueous Salt A Precipitate Is an AcidHas Carbonate IonsWater and carbon Dioxide Has Ammonium IonsHas Hydroxide IonsWater and Ammonia Is an AcidHas hydroxide IonsWater + a Salt

Practice Problems 1) Potassium carbonate and hydrochloric acid 2) Ammonium chloride and sodium hydroxide 3) Calcium carbonate and acetic acid 4) Lithium hydroxide and ammonium bromide 5) Sulfuric acid and lithium hydroxide 6) Calcium hydroxide and nitric acid

Practice Problems 1)Potassium carbonate and hydrochloric acid K 2 CO 3(aq) +2 HCl (aq)  2KCl (aq) + H 2 O (l) + CO 2(g) 2) Ammonium chloride and sodium hydroxide NH 4 Cl (aq) + NaOH (aq)  NaCl (aq) + NH 3 (g) + H 2 O (l) 3) Calcium carbonate and acetic acid CaCO 3(s) + 2HCH 3 COO (aq)  Ca(CH 3 COO) 2(aq) + H 2 O (l) + CO 2 (g) 4) Lithium hydroxide and ammonium bromide LiOH (aq) + NH 4 Br (aq)  LiBr (aq) + H 2 O (l) NH 3(g) 5) Sulfuric acid and lithium hydroxide H 2 SO 4(aq) + 2LiOH (aq)  Li 2 SO 4(aq) + 2H 2 O (l) 6) Calcium hydroxide and nitric acid Ca(OH) 2(aq) + 2HNO 3(aq)  Ca(NO 3 ) 2 (aq) +2H 2 O (l)