Chemical Formulas, Chemical Reactions and
Balancing Equations
Freiman
Compounds - Ionic
 Contain CATIONS and ANIONS
 Naming:
 1. Name cation
 2. Name anion
 Ex) CaCl2 = calcium chloride
 Ex2) Al2(SO4)3 = aluminum sulfate
 Ex3) NiS = nickel(II) sulfide
 Building Formulas:
 1. Show both ions
 2. Cross-multiply to even out the charges
 3. Write chemical formula with subscripts
Ex 1) sodium sulfide
Na+
S2x2
x1
Na2S
Ex 2) calcium nitrate
Ca2+ NO3Ca(NO3)2
**To finish, use SOLUBILITY CHART to determine
solubility in water
Compounds - Molecular
 Contains only non-metals
 Naming
 1. Name first element with prefix
 2. Name second element with prefix and IDE ending
 Ex) N2H4 – dinitrogen tetrahydride
**Prefixes: mono, di, tri, tetra, penta,
hexa, hepta, octa, nona, deca
Chemical Reaction Types
 5 common types of reactions
 Need to be able to predict products of these reactions and
then BALANCE the equation
 1. Single Replacement:
 Element “replaces” element of the same kind in new
compound
NaBr(aq) + Cl2(g)
NaCl(aq) + Br2(g)
2NaBr(aq) + Cl2(g)
2NaCl(aq) + Br2(g)
 2. Double Replacement:
 Ions “switch partners” to make two new ionic
compounds
Ca(NO3)2(aq) + Na2SO4(aq)
NaNO3(aq) + CaSO4(s)
Ca(NO3)2(aq) + Na2SO4(aq)
2NaNO3(aq) + CaSO4(s)
 3. Formation:
 Most common ionic compound is produced from
elements
Fe(s) + S8(s)
FeS(s)
8Fe(s) + S8(s)
8FeS(s)
 4. Decomposition:
 Compound breaks down into elements
KI(s)
K(s) + I2(s)
2KI(s)
2K(s) + I2(s)
 5. Combustion:
 Compound reacts with OXYGEN to produce common
oxides
 C – CO2
 N – NO2
 S – SO2
 H – H2O
 Metals – ionic metal oxide
CH4(g) + O2(g)
CO2(g) + H2O(g)
CH4(g) + 2O2(g)
CO2(g) + 2H2O(g)
Practice
 Predict the products for the following reactions and
then balance the equation