1. Ch 8 Chemical Equations and Reactions
Sec. 1 Describing Chemical Reactions
Sec 2 Balancing Chemical Equations
Sec 3 Classifying Chemical Reactions
Sec 4 Writing Net Ionic Equations

2. Sec 1 Describing Chemical Reactions
List evidence that suggests a chemical reaction has occurred and evidence that proves a chemical reaction has occurred
Describe a chemical reaction by using a word equation and a formula equation.
Interpret notations in formula equations such as those relating to states of matter or reaction conditions

3. Chemical Change Changes in energy Release of energy as heat
Release of energy as light
Production of sound
Reduction or increase of temperature
Absorption or release of electrical energy(battery)

4. Chemical Changes Formation of new substances Formation of a gas
Formation of a precipitate
Changes in color
Changes in odor

5. Chemical Changes
Some of the previous examples of evidence for a chemical change are not definite
To be certain of a chemical change, chemical analysis must be performed.
Checks of Density, melting point, and boiling are examples of how to check for a chemical change.

6. Chemical Changes Chemical reactions either release or absorb energy.
When it is released it can be considered a product
When it is absorbed it can be considered a reactant
Examples on page 262
In order for reactions to take place, the 2 molecules reacting must come into contact with one another

7. Chemical Changes
Chemical equations represent a chemical reaction with words or symbols.
How to write a chemical equation…
What do all the symbols mean?

8. Sec. 2 Balancing Equations
Relate the conservation of mass to the rearrangement of atoms in a chemical reaction.
Write and interpret a balanced chemical equation for a reaction and relate conservation of mass to the balanced equation.

9. Reactions Conserve Mass
What does the law of conservation of mass state?

10. Balancing Equations
During a chemical reaction, atoms are simply rearranged.
Following the law of conservation of mass, there must be an equal number of atoms on the product said as there is the reactant side.

11. Balancing Equations Identify the reactants and products Count atoms
Insert Coefficients (number in front of atoms or molecules in the reaction)
Verify your results
Practice, trial and error

12. Sec. 3 Classifying Chem Reactions
Identify combustion reactions, write chemical equations that predict products.
Identify synthesis reactions, write chemical equations that predict products.
Identify decomposition reactions, write chemical equations that predict products.
Identify displacement reactions, write chemical equations that predict products.
Identify double-displacement reactions, write chemical equations that predict products.

13. Reaction types Combustion Reactions
Reaction of a hydrocarbon and oxygen that produces carbon dioxide and water
CH4 + O2  CO2 + H2O

14. Reaction Types Synthesis Reactions
Two or more substances are combined to form one compound. (two reactants forming one product).
Mg + O2  MgO

15. Reaction Types Decomposition Reactions
Are the opposite of synthesis, one compound is broken down into 2 or more substances.
H2 O  H2 + O2

16. Reaction Types Displacement Reactions
When elements or compounds switch positions in a chemical reaction