1. Conservation of Mass

2. What is it?
Conservation of Mass is a principle that states that when a chemical reaction occurs matter is not created or destroyed.
This means that the total mass of the reactants MUST equal the total mass of the products.

3. Open vs. Closed system
Open system- where matter can enter the system or escape to the surroundings
Example: a burning match
Closed system- where the entire reaction is contained; nothing can enter or leave the system
Example: Pear decay (pg. 197 in book)

4. Balancing Equations
Due to Conservation of Mass we must balance all equations to make sure that we have an equal number of reactants and products of the same element to achieve the same mass on both sides.
H2O
MgO

5. Classifying Chemical Reactions
There are three major classifications of reactions
Synthesis
Decomposition
Replacement

6. Synthesis
This is when 2 or more things are combined to make a more complex substance
Water is an example of a synthesis reaction

7. Decomposition
This is like it sounds where a more complex compound is broken down into its smaller parts
Hydrogen peroxide into water and O2 gas

8. Replacement
Whenever one element takes the place of another in a compound; they switch places
Cu2O to Cu + CO2