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