1. Balancing Chemical Equations
Matter & Bonding # 5
Balancing Chemical Equations

2. Law of Conservation of Mass
The Law of Conservation of Mass states that “in a chemical reaction, the total mass of the reactants is always equal to the total mass of the products.”
This means that no matter what chemical reaction happens, matter is never created or destroyed.
It may change composition, or state, but it does not simply disappear!

3. Balancing
Just as we can measure the mass of both products and reactants, we can also measure the number of atoms of each element.
For example, if there are 2 atoms of carbon required for a reaction to happen, there will be 2 atoms of carbon in the products of that reaction.
Sometimes when we write a word equation, there is no balance of atoms between the reactants and products. To ensure a reaction proceeds in the lab, we first need to balance the equation.

4. Example 1
Al + Fe2O3 → Fe + Al2O3

5. Example 2
Cu + AgNO3 → Ag Cu(NO3)2

6. Example 3
Na + Cl2 → NaCl

7. Example 4
Nitrogen + Hydrogen → Nitrogen Trihydride

8. Example 5
Lithium Chlorate → Lithium Chloride + Oxygen

9. Example 6
Tricarbon octahydride + oxygen → carbon dioxide + water