C

CC

CB

B

Double Displacement Reaction

A

AB

BCompound AB Compound CD

A

AD

DCompound AD Compound CB

D

D

+ +

MagnesiumChloride

MgCl2

CalciumHydroxideCa(OH)2

MagnesiumHydroxideMg(OH)2

CalciumChloride

CaCl2

A

AB

BCompound AB

C

CCompound CD

D

D

• Involves the exchange of partners in the reaction

• The reaction involves two ionic compounds as reactants.

• As the equation above shows, the ions “change partners” to form the products.

• This type of reaction commonly occurs in aqueous solutions.

How much is too much?

• We can take advantage of the individual solubilities of different substances in water. – If the product of a reaction is very soluble, it

will stay in solution (aq).– If the product is only slightly soluble,

(insoluble), it is likely that more will be produced than can dissolve

Types of Double Displacement

Reactions• There are three types of double displacement reactions:

1) Precipitation Reaction2) Reactions Producing a Gas3) Neutralization Reactions

Sample Problem #1(Precipitation Rxn)

• Write a balanced equation to represent the reaction of an aqueous solution of barium chloride with an aqueous solution of ammonium sulfate. Indicate the physical state of the reactants and products involved.

Sample Problem #2

(Production of a Gas)

• Write a balanced equation to represent the reaction of hydrochloric acid and sodium sulfide.

Neutralization Reactions

• Special type of double displacement reaction

• Three types:

1. Neutralization Reactions

With a hydroxide compound• General equation:

Acid + Base --> Salt + Water

• Ex: HCl (aq)+ NaOH (aq) --> NaCl (aq) + H2O (l)

Sample Problem #3

(Neutralization Reaction)• Write the balanced chemical equation for the neutralization reaction of sodium hydroxide with hydrochloric acid

 

2. Neutralization Reactions

With a carbonate compound• General Equation Acid + carbonate compound --> water + carbon dioxide + ionic compound

• H2SO4(aq) + CaCO3(s) --> H2O(l) + CO2(g) + CaSO4 (s)

Sample Problem #4

(Neutralization Reaction)• Write the balanced chemical equation for the neutralization reaction of sodium carbonate with hydrochloric acid

3. Neutralization Reactions

With a sulphite compound• General Equation Acid + sulphite compound --> water + sulphur dioxide + ionic compound

• 2H3PO4(aq) + 3CaSO3(s) --> 3H2O(l) + 3SO2(g) + Ca3(PO4)2 (s)

Sample Problem #4

(Neutralization Reaction)• Write the balanced chemical equation for the neutralization reaction of sodium sulphite with hydrochloric acid

Homework:

• Read pp. 205 – 210• Answer p. 211 # 1 - 2