1. Types of Chemical Reactions

2. When writing Chemical Rxns…
It is important to indicate what “state” the atom/molecule is in
(s): solid
(l): liquid
(g): gas
(aq): aqueous solution – a solution in which the solvent is water
∆: heat

3. CH4(g) + 2O2(g)  CO2(g) + 2H2O(g)
A. Combustion
the burning of any substance in O2 to produce heat
For our purposes we are going to say hydrocarbons and oxygen
A + O2  CO2 + H2O
CH4(g) + 2O2(g)  CO2(g) + 2H2O(g)

4. A. Combustion C3H8(g)+ O2(g)  5 3 4 CO2(g)+ H2O(g) Products:
contain oxygen
hydrocarbons form CO2 + H2O
C3H8(g)+ O2(g) 
CO2(g)+ H2O(g)

5. Practice with combustion rxns.
Write a balanced equation for the complete combustion of the following:
Butene (g); C4H8
C4H8 + 6O2 → 4CO2 + 4H2O
Glucose (s); C6H12O6
C6H12O6 + 6O2 → 6CO2 + 6H2O
Octane (l); C8H18
2C8H O2 → 16CO2 + 18H2O

6. B. Synthesis/Combination
The combination of 2 or more substances react to form a single compound
only one product
A + B  AB

7. B. Synthesis/Combination
H2(g) + Cl2(g)  2 HCl(g)

8. B. Synthesis/Combination
Products:
ionic - cancel charges
covalent - hard to tell
Al(s)+ Cl2(g) 
AlCl3(s)

9. Practice with Synthesis Rxns.
Write balanced chemical equations for the following:
Mg + O2.
2Mg + O2 → 2MgO
P + O2 → Diphosphorous pentoxide
4P + 5O2 → 2P2 O5
Ca + S
Ca + S → CaS
Fe + O2 → Iron (II) oxide
2 Fe + O2 → 2FeO

10. AB  A + B C. Decomposition
a compound breaks down into 2 or more simpler substances
only one reactant
AB  A + B

11. C. Decomposition
2 H2O(l)  2 H2(g) + O2(g)

12. C. Decomposition 2 2 KBr(l)  K(s) + Br2(l) Products:
binary - break into elements
others - hard to tell
KBr(l) 
K(s) + Br2(l)

13. Practice with Decomposition Rxns.
Write balanced chemical equations for the following:
HBr
2HBr → H2 + Br2
NaCl
2NaCl → 2Na + Cl2
Ag2O
2Ag2O → 4Ag + O2
Mercury (II) oxide
2HgO → 2Hg + O2

14. A + BC  B + AC D. Single Replacement
one element replaces another in a compound
metal replaces metal (+)
nonmetal replaces nonmetal (-)
A + BC  B + AC

15. Cu(s) + 2AgNO3(aq)  Cu(NO3)2(aq) + 2Ag(s)
D. Single Replacement
Cu(s) + 2AgNO3(aq)  Cu(NO3)2(aq) + 2Ag(s)

16. D. Single Replacement Products: metal  metal (+)
nonmetal  nonmetal (-)
free element must be more active (check activity series)

17. D. Single Replacement Fe(s)+ CuSO4(aq)  Cu(s)+ FeSO4(aq)
Br2(l)+ NaCl(aq) 
N.R.

18. Practice w/Single Replacement Rxns.
Write balanced chemical equations for the following:
Mg(s) + Zn(NO3)2(aq)
Mg(s) + Zn(NO3)2(aq) → Mg (NO3)2(aq)+ Zn(s)
Mg(s) + LiNO3(aq)
Mg(s) + LiNO3(aq) → No rxn.
Al + H2SO4
2Al +3H2SO4 → Al2(SO4)3 + 3H2
Li + H2O
2Li + 2H2O → 2LiOH + H2

19. AB + CD  AD + CB E. Double Replacement
ions in two compounds “change partners”
cation of one compound combines with anion of the other
AB + CD  AD + CB

20. Pb(NO3)2(aq) + K2CrO4(aq)  PbCrO4(s) + 2KNO3(aq)
E. Double Replacement
Pb(NO3)2(aq) + K2CrO4(aq)  PbCrO4(s) + 2KNO3(aq)

21. E. Double Replacement Pb(NO3)2(aq)+ KI(aq)  2 2 PbI2(s)+ KNO3(aq)
Products:
switch negative ions
one product must be insoluble (check solubility table in CRM)
Pb(NO3)2(aq)+ KI(aq) 
PbI2(s)+ KNO3(aq)
NaNO3(aq)+ KI(aq) 
N.R.

22. Practice with Double Displacement Rxns.
Write balanced chemical equations for the following:
HCl + Ca(OH)2
2HCl + Ca(OH)2 → N.R.
KOH + H3PO4
3KOH + H3PO4 → K3PO4 + 3H2O
Al(OH)3+ H2SO4
2Al(OH)3+ 3H2SO4 → Al2(SO4)3+ 6H2O
SrBr2 + (NH4)2CO3
SrBr2 + (NH4)2CO3 → 2NH4Br + SrCO3