CH 8 Chemical Equations and

ReactionsSection 3

Classifying Chemical Reactions

5 reaction types:Single Replacement (displacement)Double Replacement (displacement)CombustionSynthesisDecomposition

Single Replacement Also called “displacement”

Generic form:

A + BC AC + B

A single element (A) reacts with a compound (BC), and replaces an element from the compound.

[A kicks out B]

Single Replacement cont. A pure metal may replace a metal (or H) in

a compound.

Cu + AgNO3 identify the pure metal:identify the metal (or H) in the compound:

Copper is a candidate to replace silver, and it will.Cu + AgNO3 Ag + CuNO3

Single Replacement: Activity Series Not all metals are active enough to

replace a metal (or H) in a compound. The activity series ranks the elements in

order of “strength”, those high on the list will replace those below.

Single Replacement Reactions Identify the element in the compound to

be replaced

A) Li + CuCl2

B) Fe + AgNO3

1. Li2. K3. Ba4. Sr5. Ca6. Na7. Mg8. Al9. Mn10. Zn11. Cr12. Fe13. Co14. Ni15. Sn16. Pb17. H18. Cu19. Hg20. Ag21. Pt22. Au

Activity Series of Metals

1. Li2. K3. Ba4. Sr5. Ca6. Na7. Mg8. Al9. Mn10. Zn11. Cr12. Fe13. Co14. Ni15. Sn16. Pb17. H18. Cu19. Sn20. Ag21. Pt22. Au

1. Li2. K3. Ba4. Sr5. Ca6. Na7. Mg8. Al9. Mn

10.Zn11.Cr12.Fe13.Co14.Ni15.Sn16.Pb17.H18.Cu19.Hg20.Ag21.Pt22.Au

Practice: Will calcium replace Cobalt? Will Sodium replace magnesium? Will Lead replace Zinc? Will Lithium replace… Will gold replace… Will sodium replace Potassium?

Practice equations Aluminum is dipped into Zinc Nitrate solution.

Sodium is placed into cold water.

Gold is added to a solution of calcium chloride.

Magnesium is dipped into nickel (II) chloride solution.

Lead is placed into an iron (III) nitrate solution.

Zinc is added to a solution of copper (II) sulfate.

Predict the products of the following reactions: Ca + CuSO4

Al + KNO3

Single replacementthe “other” activity series A more active

halogen will replace a less active halogen

1. F2. Cl3. Br4. I5. At

Cl2 + KI

Cl2 + KF

Decomposition Reactions

Binary CompoundsBinary Compounds Break into the elements 2 HgO 2 Hg + O2

Ternary Compounds…escaping gasTernary Compounds…escaping gas Metal CarbonateMetal Carbonate breaks into metal oxide and CO2

CaCO3 CaO + CO2

Generic form: AB A + B

Determine the reaction category, Predict the products and balance them.Br2 + NaI

CH4 + O2

C6H14 + O2

Combustion ReactionsGeneric form: CxHy + O2 CO2 + H2O

A hydrocarbon uses oxygen from the air to produce Carbon Dioxide and Water.

C2H6 + O2 CO2 + H2O

Complete combustion always produces carbon dioxide and water.

A “hydrocarbon” may also include an oxygen

C3H7OH + O2 CO2 + H2O

Synthesis (Combination) 2 elements2 elements combine to form an ionic

compound.2 K + Cl2 2 KCl

A metal oxidemetal oxide and waterwater combine to form a base. (a base is a hydroxide compound)

MgO + HOH Mg(OH)2

Li2O + HOH 2 LiOH

Generic Form: A + B AB

Synthesis (Combination)A non-metal oxidenon-metal oxide and waterwater combine to form

an acid. (an acid starts with “H”) CO2 + H2O H2CO3

Carbon dioxide + water Carbonic acid

SO2 + H2O H2SO3 Sulfur Dioxide + water Sulfurous acid

Double Replacement Reactions

2 ionic compounds2 ionic compounds “switch + partners”. A solid precipitate, a gas, or water forms

Ba(NO3)2 + Na2SO4

BaSO4 + NaNO3

Make sure the new ionic compounds have no net

charge.

Generic form: AB + CD AD + CB

Types of Chemical Reactions Lab

Pb(NO3)2 + KI

Mg + HCl

H2O2

NaHCO3 (+heat)

Electrolysis of H2O