Transcript Chapter 21: Types of Reactions

Integrated Science
Unit 7, Chapter 21
Unit Seven: Changes in Matter
Chapter 21 Types of Reactions
21.1
Chemical Changes
21.2
Chemical Equations
Chapter 21 Learning Goals

Distinguish between different types of reactions.
 Given the reactants, identify the type of reaction that
will occur and predict the products that will be
produced.
 Analyze energy changes that accompany chemical
reactions and classify them as exothermic or
endothermic.
 Observe reactions of household chemicals to develop
a set of rules for precipitate formation. Use these rules
to make predictions.

Demonstrate safe practices during laboratory
investigations.
Chapter 21 Vocabulary Terms

addition reaction

exothermic reaction

combustion reaction

polymerization

decomposition reaction

precipitate

dissolution reaction

reaction insoluble

double-displacement


endothermic reaction
single-displacement
reaction
21.1 Classifying Reactions

Being able to recognize the types
of reactions will help you predict
what types of substances will be
produced.
21.1 Types of Reactions
Addition Reaction
A
+
B -----> AB
Fe (s) + O2 (g) -----> Fe2O3 (s)
Remember:
4 Fe + 3 O2
-----> 2 Fe2O3
21.1 Types of Reactions:
Decomposition Reaction
AB
----->
A
+
2 H2O (l) -electricity-> 2 H2 (g)
2 NaHCO3
(s)
-heat->
2 H2 (g)
B
+
O2 (g)
+ NaCO3 (g)
21.1 Types of Reactions:
Single Displacement Reaction
A + XB
Fe +
CuCl
CuCl2
----->
+
----->
----->
+
+
21.1 Types of Reactions:
Double Displacement Reaction
AB
+
CD --> AC + BD
Pb(NO3)2 + 2 KI --> PbI2 + 2 KNO3
21.1 Types of Reactions:
Combustion Reaction
CxHy + O2 ---> CO2 + H2O + energy
C6H12O6 + 6 O2 ---> 6 CO2 + 6 H2O
21.1 Precipitation
21.1 Classifying Reactions
Key Question:
How can you predict the products of a reaction?
?
*Read text section 21.1 BEFORE Investigation 21.1
21.2 Energy in Reactions
Key Question:
How can you classify reactions
based on energy?
*Read text section 21.2
AFTER Investigation 21.2
21.2 Energy in Reactions
Exothermic reactions produce energy.
C6H12O6 + 6 O2 ---> 6 CO2 + 6 H2O + energy
Photosynthesis takes place in the leaves of plants.
21.2 Energy in Reactions
Endothermic reactions require more energy
than they produce.
2 Al2O3 (s) + energy ---> 4 Al (s) + 3 O2 (g)
Aluminum is refined from aluminum ores.