A Balance Equation
According to the Law of Conservation of Mass, atoms cannot be created or eliminated in the process of a chemical reaction. Therefore, the amount of atom of each element before reaction must be equal after the reaction.
Example:
Balance the following chemical equations:
- Mg + O2 → MgO
- CuO + H2 → Cu + H2O
- Na + H2O → NaOH + H2
- Li + Cl2 → LiCl
Answer:
a.
2Mg + O2 → 2MgO
c.
2Na + 2H2O → 2NaOH + H2
d.
2Li + Cl2 → 2LiCl
Writing a Balance Equation
Example:
Lead(II) nitrate aqueous reacts with potassium iodide aqueous to produce lead(II) iodide precipitate and potassium nitrate aqueous.
Answer: