1. Chemical Equations – Outcomes
Give chemical formulas of covalent and ionic compounds.
Write chemical equations.
Interpret chemical equations.
Balance chemical equations.

2. Give Chemical Formulas (Covalent)
The table shows some of the covalent compounds that come up on our course:
Compound
Formula
Course Section
Hydrogen chloride (hydrochloric acid)
HCl
Acids and bases, environment.
Water
H2O
Water, loads of other places
Methane (natural gas)
CH4
Environment, fuel, energy
Carbon dioxide
CO2
Carbon dioxide, environment, atmosphere
Hydrogen Peroxide
H2O2
Atmosphere

3. Give Chemical Formulas (Ionic)
The table shows some of the ionic compounds that appear on our course:
Compound
Formula
Course Section
Sodium chloride
NaCl
Acids and bases
Magnesium oxide
MgO
Atmosphere
Iron sulfide
FeS
Compounds
Calcium chloride
CaCl2
Water
Copper sulfate
CuSO4
Solutions
Calcium carbonite
CaCO3
Carbon dioxide
Manganese dioxide
MnO2
Sodium Hydroxide
NaOH

4. Write Chemical Equations
Word equations are written using the names of compounds involved in a reaction.
e.g. ℎ𝑦𝑑𝑟𝑜𝑔𝑒𝑛+𝑜𝑥𝑦𝑔𝑒𝑛→𝑤𝑎𝑡𝑒𝑟
e.g. 𝑐𝑎𝑟𝑏𝑜𝑛+𝑜𝑥𝑦𝑔𝑒𝑛→𝑐𝑎𝑟𝑏𝑜𝑛 𝑑𝑖𝑜𝑥𝑖𝑑𝑒
The particles on the left hand side of the equation are called reactants.
The particles on the right hand side of the equation are called products.

5. Write Chemical Equations
Chemical equations use chemical formulas instead of the names of chemicals.
e.g. 𝐻 2 + 𝑂 2 → 𝐻 2 𝑂
e.g. 𝐶+ 𝑂 2 →𝐶 𝑂 2
We still call the particles on the left reactants and the particles on the right products.

6. Interpret Chemical Equations
Write the word equation versions of the following chemical equations:
𝐻𝐶𝑙+𝑁𝑎𝑂𝐻→𝑁𝑎𝐶𝑙+ 𝐻 2 𝑂
𝐾+ 𝑂 2 → 𝐾 2 𝑂
𝑍𝑛+𝐻𝐶𝑙→𝑍𝑛𝐶 𝑙 2 + 𝐻 2
𝐻 2 𝑂 2 𝑀𝑛 𝑂 2 𝐻 2 𝑂+ 𝑂 2
𝐶𝑎𝐶 𝑂 3 +𝐻𝐶𝑙→𝐶𝑎𝐶 𝑙 2 + 𝐻 2 𝑂+𝐶 𝑂 2

7. Balance Chemical Equations
A “balanced” chemical equation also has equal amounts of each atom on each side of the equation.
e.g. 𝐻 2 + 𝑂 2 → 𝐻 2 𝑂
is not a balanced equation, as there are two oxygens on the left, but only one on the right.
Chemical formulas CANNOT change, so we multiply the molecules instead:
e.g. 𝐻 2 + 𝑂 2 →2 𝐻 2 𝑂
but now there are not enough hydrogens on the left:
e.g. 2 𝐻 2 + 𝑂 2 →2 𝐻 2 𝑂
is a balanced equation.

8. Balance Chemical Equations
Balance the following chemical equations:
𝐾+ 𝑂 2 → 𝐾 2 𝑂
𝑍𝑛+𝐻𝐶𝑙→𝑍𝑛𝐶 𝑙 2 + 𝐻 2
𝐻 2 𝑂 2 𝑀𝑛 𝑂 2 𝐻 2 𝑂+ 𝑂 2
𝐻𝐶𝑙+𝑁𝑎𝑂𝐻→𝑁𝑎𝐶𝑙+ 𝐻 2 𝑂
𝐶𝑎𝐶 𝑂 3 +𝐻𝐶𝑙→𝐶𝑎𝐶 𝑙 2 + 𝐻 2 𝑂+𝐶 𝑂 2
𝐶𝑎 𝑂𝐻 2 +𝐶 𝑂 2 →𝐶𝑎𝐶 𝑂 3 + 𝐻 2 𝑂