1. Review… Write as symbols:
6 atoms of solid potassium metal reacts with 1 molecule of nitrogen gas when heated to produce 2 formula units of solid potassium nitride.

2. Review… Write as symbols:
6 atoms of solid potassium metal reacts with 1 molecule of nitrogen gas when heated to produce 2 formula units of solid potassium nitride.
6 K(s) N2(g)  2 K3N(s)

3. Review… Balance the following equations:
___ KMnO4  ___ K2O ___ MnO + ___ O2
___ Al2O ___ Cl2  ___ AlCl ___ O2
___ C6H12O6 + ___ O2  ___ H2O + ___ CO2
___ NaBr + ___ CaF2  ___ NaF ___ CaBr2

4. Review… Balance the following equations:
4 KMnO4  2 K2O MnO O2
2 Al2O Cl2  4 AlCl O2
C6H12O O2  6 H2O CO2
2 NaBr + CaF2  2 NaF + CaBr2

5. 5 ½ Types of Chemical Reactions

6. Combination Reaction
Multiple reactants combine together to form one product.
A B  AB
Example:
2 Mg(s) + O2(g)  2MgO(s)
A B AB

7. Decomposition Reaction
A single reactant breaks down into two or more products. It decomposes.
AB  A B
Example:
2 NaN3(s)  2Na(s) N2(g)
AB A B

8. Single- Replacement Reaction
Single- Replacement Cationic
One cation replaces a second cation in a compound.
A + BC  B + AC
Example:
2K(s) + 2 HOH(l) 2KOH(aq) + H2(g)
A BC AC B
Single- Replacement Anionic
One anion replaces a second anion in a compound.
A + BC  BA + C
Example:
Br2(aq) + 2NaI(aq)  2NaBr(aq) + I2(aq)
A BC BA C

9. Single- Replacement Reaction Continued
To tell if a reaction occurs, look at the activity series chart.
A more reactive metal will replace a less reactive metal.
Halogen reactivity decreases as you go down the column

10. Double- Replacement Reactions
Both cations get exchanged
Normally forms a precipitate, gas, or water.
AB + CD  CB + AD
Example:
Na2S(aq) + Cd(NO3)2(aq)  CdS(s) + 2NaNO3(aq)
AB CD CB AD

11. Double-Replacement Reaction Continued
Use solubility chart to determine the state of the products.

12. Hydrocarbon + oxygen  carbon dioxide + water
Combustion Reaction
A reaction where an element or compound reacts with oxygen to produce energy.
Reactants are oxygen and a hydrocarbon. Products are always carbon dioxide and water
Hydrocarbon + oxygen  carbon dioxide + water
Example:
CH4(g) + 2O2(g)  CO2(g) + 2H20(g)