1. Synthesis, Decomposition, Single,
or Double Replacement?
1. N2 + 3H2 2NH3
1. Synthesis
2. 2Br2 + 2H2O  4HBr + O2
2. Singe
Replacement
3. 2KBr + H2SO4  K2SO4 + 2HBr
3. Double
Replacement
4.
4. H2SO3  H2O + SO2 Decomposition

2. Review
Types of chemical
reactions:
Synthesis
Decomposition
Replacement: single and
double

3. Balancing Equations
Balanced equation- correct
coefficients in place so the same
numbers of, and types of, atoms
appear on both sides of the
equation

4. Balancing Equations
 2H2 + (1)O2  2(H2O(1))
4 hydrogen's +
2 oxygen's 
2 water molecules

5. Balancing Equations
2H2 + (1)O2  2(H2O(1))
4 H’s on the left and right
2 O’s on the left and right

6. Balancing Equations
2H2 + O2  2H2O
 Only change coefficients-
big numbers in front of
equations
 Not subscripts- little
numbers after equations

7. Zn
+
HCl

ZnCl2
+
H2

8. K
+
H 2O

KOH
+
H2

9. H 2O 2
+
PbS

PbSO4 +
H 2O

10. Mg
+
H 2O

Mg(OH)2
+
H2

11. H2 +
H2O2
Na
O2  H2O

+ O2
H2O

+
Na2O
O2

12. N2 +
H2
P4 +
O2
C +
H2

NH3

P4O6

CH4

13. Al2O3

Fe + H2O
Al +

O2
Fe3O4 +
H2

14. C2 H6 + O 2 
CO2 + H2O

15. Na2SO4 + CaCl2
CaSO4 +
NaCl