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.

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) + 1 N2(g)  2 K3N(s)

Review… Balance the following equations: ___ KMnO4  ___ K2O + ___ MnO + ___ O2 ___ Al2O3 + ___ Cl2  ___ AlCl3 + ___ O2 ___ C6H12O6 + ___ O2  ___ H2O + ___ CO2 ___ NaBr + ___ CaF2  ___ NaF + ___ CaBr2

Review… Balance the following equations: 4 KMnO4  2 K2O + 4 MnO + 5 O2 2 Al2O3 + 6 Cl2  4 AlCl3 + 3 O2 C6H12O6 + 6 O2  6 H2O + 6 CO2 2 NaBr + CaF2  2 NaF + CaBr2

5 ½ Types of Chemical Reactions

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

Decomposition Reaction A single reactant breaks down into two or more products. It decomposes. AB  A + B Example: 2 NaN3(s)  2Na(s) + 3N2(g) AB A B

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

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

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

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

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)