Law of Conservation of Mass

Law of Conservation of Mass

by Carla Elkins

Poll

How many types of atoms are here?

• 1

• 2

• 3

• 0

Poll

Which could be the chemical formula for this molecule?

• 3C

• C₃

• 3+C

• ?

Poll

Which of the following could this molecule represent?

• N₃

• N₂

• CO₂

• 2CO

Multiple Choice

Which of the following could this model represent?

• O₂

• NO₃

• H₂O

• 2O

Multiple Choice

Which chemical formula could this molecule represent?

• H₂O₃

• H₃O₂

• H₂O₄

• H₂O₂

​CHEMICAL REACTIONS

​There are three parts to a chemical reaction.

​C + O₂ ---> CO₂

​

​How do we remember the parts?

Poll

The reactants in a chemical reaction are 

• what you start with

• what you end with

• where the chemical reaction takes place

• I have no idea

Poll

The yield sign in the chemical reaction is

• what you start with

• what you end with

• where the chemical reaction takes place

• I have no idea

Poll

The products in the chemical reaction are

• what you start with

• what you end with

• where the chemical reaction takes place

• I have no idea

Multiple Choice

What is the left part of a chemical equation called?
H_{2 +} O → H₂O

• Reactants
• Products 
• Yields 
• Chemical Equation 

REACTANTS must equal PRODUCTS

Poll

If there  are 6 Oxygens in the reactants then there must be how many Oxygens in the products?

• 6

• 1

• 3

• Half

​Does this follow the Law of Conservation of Mass?

​​1. Count the number of each type of atom on the Reactant side.

​

​2. Is it equal to the number of each type of atom on the Product Side?

​

​3. Equal= Does follow LOCOM

Not Equal= Does not follow LCOM

Poll

Does this follow LOCOM?

• yes

• no

• I have no idea

Multiple Choice

Does this follow LOCOM?

• yes

• no

Multiple Choice

Does this follow LOCOM?

• yes

• no

Multiple Choice

What is the right part of a chemical equation called?
H_{2 +} O → H₂O

• Reactants
• Products 
• Yields 
• Chemical Equation 

3 THINGS TO ​REMEMBER:

1. THE LAW OF CONSERVATION OF MASS states that NOTHING can APPEAR or DISAPPEAR.

​

2. ​Matter CANNOT be CREATED or DESTROYED.

​

3. ​PRODUCTS = REACTANTS

Multiple Choice

Matter can

• appear

• disappear

• never appear or disappear

• sometimes appear or disappear

Multiple Choice

Do reactants ALWAYS have to equal products in a chemical reaction?

• yes

• no