2.1 Balancing Equations

Exam 2

What is the Law of Conservation of Mass?

Mass cannot be created or destroyed in a chemical reaction; atoms must be balanced on both sides of the equation.

What is the first step in balancing a chemical equation?

Identify the correct formulas for all reactants and products.

What do you adjust to balance a chemical equation?

The coefficients (not the subscripts).

What does a balanced chemical equation show?

The same number of each type of atom on both sides of the reaction.

Balance this equation: H₂ + O₂ → H₂O

2H₂ + O₂ → 2H₂O

Balance this equation: Fe + O₂ → Fe₂O₃

4Fe + 3O₂ → 2Fe₂O₃

True or False: You should always balance oxygen and hydrogen first.

False. Balance everything else first, and leave H and O for last.