Classifying Chemical ReactionsSection 10.2

Objectives

Classify chemical reactions Identify the characteristics of

different classes of chemical reactions

Key Terms

Synthesis reaction

Combustion reaction

Decomposition reaction

Single-replacement reaction

Double-replacement reaction

precipitate

5 Types of Reactions

Synthesis Combustion Decomposition Single-Replacement Double-Replacement

Synthesis Reaction

Two or more substances combine to form one single product. A + B ABEx: 2Na(s) + Cl2(g) 2NaCl(s)

Combustion Reaction Oxygen combined with a

substance releasing energy (light and heat)

Many combustion reactions are also synthesis reactionsEx: 2H2(g) + O2 2H2O(g)

Decomposition reactions One compound breaks down into

2 or more compounds or elements Often requires energy Setup: AB A + B

Ex: NH4NO3(s) N2O(g) + 2H2O(g)

Heat was required

Replacement Reactions Replacement of an element in a

a compound 2 kinds of replacement

reactions:Single Double

Single Replacement Reactions

Atoms of one element replace the atoms of another element in a compound

Setup: A+ BX AX + B

Activity Series of Metals

Whether or not a metal will replace another metal or any other substance depends on its reactivity

Figure 10-10 on page 288 Metals can replace any metal

BELOW it on the series. Not ABOVE it (NR)

Practice Problems

Page 289

Double Replacement Reactions

Involves the exchange of ions between 2 compounds

Setup: AX + BY AY + BX If a solid is produced during the

reaction it is called a precipitate

Practice Problems

Page 291

Homework

Page 291 #27-32