The Law of Conservation of Mass

Law of Conservation of Mass

Means, that the amount of mass a reaction starts with must be equal to the amount of mass that it must end with

OR PERHAPS MORE SCIENTIFICALLY -

Matter cannot be created or destroyed.

Multiple Choice

What is the Law of Conservation of mass?

• Matter cannot be created nor destroyed

• Matter can be created and destroyed

• Matter can only be created

• Matter can only be destroyed

-Ms Lockwood

So... here are some questions for you to consider what that actually MEANS

Multiple Choice

Bob puts 200 g of ice into a pitcher with 900 g of water. He gets distracted and comes back later to find that the ice has melted in the water. How many grams of water does Bob now have in the pitcher?

• 200 g

• 700 g

• 1100 g

• 900 g

Multiple Choice

32 g of oxygen completely reacts with 8 g of hydrogen to produce ___ g water

• 8

• 12

• 24

• 40

Multiple Choice

What will weigh more when a chemical change is complete?  The reactants before the chemical reaction, or the product after the reaction is complete?

• They both will weigh the same

• The product always weighs more than the reactant

• The reactant will weigh more than the product

• They both will loose mass after the reaction

Open Ended

Write down what you understand the law of conservation to mean...

Multiple Choice

Can you determine how quickly reaction has occurred by measuring the products formed?

• Yes

• No

Since the mass of products formed is equal to the mass of reactants used, we can absolutely use the amount of product form to determine the speed of a reaction