Learning Objective

In this lesson we will learn how to write chemical equations in a way that reflects the Law of Conservation of Mass.

Learning Outcomes

By the end of this lesson you will be able to:

  • Define the Law of Conservation of Mass.
  • Explain how the Law of Conservation of Mass applies to chemical reactions.
  • Write a balanced chemical equation.

 
writing balanced chemical equations lesson contents

(Image: designua, Adobe Stock)

Lesson Topics

1 | Conservation of Mass

2 | Chemical Equations

3 | Balancing Chemical Equations

4 | Tips for Balancing Chemical Equations

 


Lesson Summary

  • The Law of Conservation of Mass states that matter is neither created nor destroyed.
  • To reflect the conservation of mass in a chemical reaction, chemical equations need to be balanced.
  • Equations are balanced by adding coefficients (numbers) in front of the chemical formulas of reactants and products.
  • A balanced equation shows equal numbers of each type of atom on both sides of the equation.
  • It reflects the ratios of each reactant and product involved in the reaction.
  • Steps for writing a balanced chemical equation:
  • Write the formula equation showing all reactants and products.
  • Tally up the total numbers of each type of atom for both sides of the equation.
  • Place coefficients in front of reactants and products until there are equal numbers of each type of atom on both sides of the equation.

 
writing balanced chemical equations diagram

 


 
writing balanced chemical equations worksheet

Click image to preview the worksheet for this lesson.

 
 
year 9 chemistry pdf workbook

Click image to preview the Year 9 Chemistry Workbook (PDF version).

 
 
Year 9 Chemistry Print Workbook Australian Curriculum

Click image to preview the Year 9 Chemistry Workbook (print version).

 
 
year 9 chemistry lesson notes australian curriculum

Click image to preview the Year 9 Chemistry Lesson Notes.