1. 14.2 Balancing Chemical Equations
H2 + O H20
Reactants = Products
Left side = Right side

2. When balancing equations:
The CAN”T be changed
The CAN be changed
2H2 + O H20

3. Coefficients must be whole numbers
After writing the chemical equation, make a table of
Balance each element, using
H O2  H2O Reactants (BEFORE) Products (AFTER)

4. 2H2 + O2  2H20    molecules atoms What must be conserved?
What does this mean?
What law ?

5. Mass is conserved and the number of atoms are also conserved
Mass is conserved and the number of atoms are also conserved. This means that if we have 100 atoms on the reactant side, we must have 100 atoms on the product side.
H2 + O2  H2O Balance this equation (coefficients)
2H2 + O2  2 H2O Determine out how many atoms
Atoms are equal on both sides so they are

6. Recall Earlier Example
When beryllium chloride reacts with sodium bromide, beryllium bromide and sodium chloride are formed.
Write Word Equation:
beryllium chloride + sodium bromide beryllium bromide + sodium chloride
Write Unbalanced Chemical Equation:
___BeCl2 + ___NaBr ___BeBr2 + ___NaCl