This document defines and describes chemical reactions. It explains that in a chemical reaction, atoms rearrange to form new compounds, with old bonds breaking and new bonds forming. Chemical reactions can be represented by chemical equations that show the reactants and products. Reactions can be exothermic, releasing energy, or endothermic, absorbing energy. They can also vary in reaction rate. The document also covers the law of conservation of matter, balancing chemical equations, and the main types of chemical reactions: synthesis, decomposition, single replacement, double replacement, and combustion reactions.

2. Chemical Reaction
What is a chemical
reaction?
• Atoms rearrange to create one or more
new compounds.
• In other words, old bonds break and
new bonds form.

3. Chemical Reaction
OLD NEW

4. Chemical Reaction
OLD NEW
Reactants Products

5. Chemical Equation
Reactants  Products
YEILD OR =
Reactants and products can be
represented by using
chemical formulas or
compound names.

6. Chemical Equation
2 H2 (g) + 1 O2 (g)  2 H2O (g)
Reactants Products
Yield or =

7. Chemical Reactions can
1.Absorb or release
energy.
1.Fast or Slow

8. Absorb energy or release
energy?

9. Exothermic- release of energy.
 Exo- Think exit!
 Thermic – heat
Endothermic- absorption of
energy
 Endo- Taken in
 Thermic – heat
Chemical Reactions can
be…

11. 2. Fast or slow
The speed of a chemical reaction is
different for all!
Depends on the reactants.
Chemical Reactions can
be…

12. Reaction Rate Activity- the
speed a reaction going from
reactants to products.

13. Law of Conservation of
Matter
The law of conservation of matter
states that matter (mass) can neither
be created nor destroyed. It
can, however, can be rearranged.
In a chemical reaction, the mass of the
reactants must equal the mass of the
products.

14. Law of Conservation of
Matter
The law of conservation of matter
states that matter (mass) can neither
be created nor destroyed. It can,
however, can be rearranged.
In a chemical reaction, the mass of the
reactants must equal the mass of the
products.
WHAT
??????

15. Think of a Balance
 Everything must be equal.
 When matter goes through a physical or
chemical change, the amount (or mass) of
the substances that you begin with must
equal the amount (or mass) of the
substances that you end with.
 BEFORE MASS MUST = THE AFTER MASS!
WHY you ask!!!!!!!

16. How do we balance
chemical equations?!?!?!
1.USE A PENCIL!!
2.Identify reactants and products
3. Make a Table!!!

17.  EXAMPLE:
H2O2 O2 + H2O
How do we balance
chemical equations?!?!?!
How many of each element is in the
reactants?
How many of each element is in the
products?
Element w/o coeff. X coeff. Total Element w/o coeff. X coeff. Total

18.  EXAMPLE:
KClO3KCl + O2
How do we balance
chemical equations?!?!?!
How many of each element is in the
reactants?
How many of each element is in the
products?
Element w/o coeff. X coeff. Total Element w/o coeff. X coeff. Total

19.  EXAMPLE:
CH4 + O2 CO2 + H2O
How do we balance
chemical equations?!?!?!
How many of each element is in the
reactants?
How many of each element is in the
products?
Element w/o coeff. X coeff. Total Element w/o coeff. X coeff. Total

20. Types of Reactions

21.  1. Synthesis-
 Two or more simple substances are combined to
form one new and more complex substance.
Types of Reactions
A + B  AB

22.  1. Synthesis-
 Two or more simple substances are combined to
form one new and more complex substance.
Types of Reactions
A + B  AB
2Na + Cl2 2NaCl

23.  2. Decomposition Reaction-
 A more complex substance breaks down into its more
simple parts.
Types of Reactions
AB  A + B

24.  2. Decomposition Reaction-
 A more complex substance breaks down into its more
simple parts.
Types of Reactions
AB  A + B
H2O2 O2 + H2O

25.  3. Single-Replacement-
 A free uncombined element replaces another combined
element in a compound.
Types of Reactions
AB + C  AC + B

26.  3. Single-Replacement-
 A free uncombined element replaces another combined
element in a compound.
Types of Reactions
AB + C  AC + BLiCl + Br2LiBr + Cl2

27.  4. Double Replacement Reaction-
 The reacting parts of two compounds switch places to
form two new compounds.
Types of Reactions
AB + CD  AD + BC

28.  4. Double Replacement Reaction-
 The reacting parts of two compounds switch places to
form two new compounds.
Types of Reactions
AB + CD  AD + BC
CaF2 + LiSO4 CaSO4 + LiF

29.  5. Combustion Reaction- OR Burning Reaction
 Involves the combination of a substance with oxygen to give
off heat and light.
Types of Reactions
AB + O2 Heat+ Light

30.  5. Combustion Reaction- OR Burning Reaction
 Involves the combination of a substance with oxygen to give
off heat and light.
Types of Reactions
AB + O2 Heat+ Light
CH4 + O2 CO2 + H2O

31. Types of Reactions
Use the code below to classify each reaction.
S = Synthesis D = Decomposition SR = Single Replacement DR = Double Replacement
____ P + O2 → P4O10 ____ Mg + O2 → MgO
____ HgO → Hg + O2____ Al2O3 → Al + O2
____ Cl2 + NaBr → NaCl + Br2 ____ H2 + N2 → NH3