1. Types of Chemical Reactions
Chemical Equations & Reactions
Types of Chemical Reactions

2. General Types of Reactions
Simple Binary (only 2 elements involved)
Synthesis
Decomposition
“Redox” (Oxidation-reduction)
Single Replacement
Combustion
“Double Replacement”
Precipitate
Acid-Base

3. A + B  AB Synthesis also known as a combination reaction
the combination of 2 or more substances to form a compound
only one product
A + B  AB

4. Synthesis 2 Al(s)+ 3 Cl2(g)  2 AlCl3(s) Products:
ionic ~ cancel charges
covalent ~ hard to tell
2 Al(s)+ 3 Cl2(g) 
2 AlCl3(s)

5. Decomposition
a compound breaks down into 2 or more simpler substances
only one reactant
most occur only when energy in the form of electricity or heat is added
AB  A + B

6. Decomposition
2 H2O(l)  2 H2(g) + O2(g)
Electrolysis
of Water

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

8. Decomposition NOT Dissociation
products in decomposition reactions are neutral molecules or atoms
Dissociation– when soluble, ionic compounds separate into ions
no NEW substance produced
physical not chemical change
More on that later…. 
NaCl(s) 
Na1+(aq) + Cl1-(aq)

9. CH4(g) + 2O2(g)  CO2(g) + 2H2O(g)
Combustion
the burning of any substance in O2 releasing energy (exothermic) in the form of light and heat
A + O2  B
CH4(g) + 2O2(g)  CO2(g) + 2H2O(g)

10. Combustion 4 Na(s) + O2(g)  2 Na2O(s) Products: Must contain oxygen
Hydrocarbons (CxHx) form CO2 + H2O
4 Na(s) + O2(g) 
2 Na2O(s)
C3H8(g) + 5 O2(g) 
3 CO2(g) + 4 H2O(g)

11. A + BC  B + AC Single Replacement also known as displacement
one element replaces another in a compound
metal replaces metal (+)
nonmetal replaces nonmetal (-)
A + BC  B + AC

12. Cu(s) + 2AgNO3(aq)  Cu(NO3)2(aq) + 2Ag(s)
SR - Example
Cu(s) + 2AgNO3(aq)  Cu(NO3)2(aq) + 2Ag(s)

13. The Activity Series of Metals
Lithium
Potassium
Calcium
Sodium
Magnesium
Aluminum
Zinc
Chromium
Iron
Nickel
Lead
Hydrogen
Bismuth
Copper
Mercury
Silver
Platinum
Gold
Metals can replace other metals
provided that they are above the
metal that they are trying to
replace.
Increasing Activity
Metals above hydrogen can
replace hydrogen in acids.
Metals from sodium upward can
replace hydrogen in water.
See back of PT!!

14. The Activity Series of the Halogens
Halogens can replace other
halogens, if they are above the halogen that they are trying to replace on the periodic table.
Fluorine
Chlorine
Bromine
Iodine
2NaCl(s) + F2(g) 
2NaF(s) + Cl2(g)
???
MgCl2(s) + Br2(g) 
No Reaction
???

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

16. Pb(NO3)2(aq) + K2CrO4(aq)  PbCrO4(s) + 2KNO3(aq)
DR - Example
Pb(NO3)2(aq) + K2CrO4(aq)  PbCrO4(s) + 2KNO3(aq)

17. Double Replacement NaNO3(aq) + KI(aq)  N.R. Products:
switch negative ions
one product MUST BE (insoluble) precipitate, water, or gas (check solubility rules on back of PT)
Pb(NO3)2(aq) + 2 KI(aq) 
PbI2(s) + 2 KNO3(aq)
NaNO3(aq) + KI(aq) 
N.R.