Law of conservation of mass

Front

What is the Law of Conservation of Mass?

Back

The Law of Conservation of Mass states that in a closed system, the mass of the reactants before a chemical reaction is equal to the mass of the products after the reaction.

Front

What evidence supports the Law of Conservation of Mass in a chemical reaction?

Back

The total mass of the reactants before the reaction is equal to the total mass of the products after the reaction.

Front

What does it mean for a chemical reaction to be balanced?

Back

A chemical reaction is balanced when both sides have the same number of atoms of each element.

Front

If a reaction starts with 20g of reactants, how much mass should the products have?

Back

The products should also have a total mass of 20g.

Front

In the reaction A + B -> C, if A has 5g and C has 9g, how much does B weigh?

Back

B weighs 4g.

Front

What happens to the mass of ice when it melts in water?

Back

The mass of the melted ice is added to the mass of the water, so the total mass remains the same.

Front

If 200g of ice is added to 900g of water, what is the total mass in the pitcher after the ice melts?

Back

The total mass is 1,100g.

Front

What is a reactant in a chemical reaction?

Back

A reactant is a substance that undergoes a change during a chemical reaction.

Front

What is a product in a chemical reaction?

Back

A product is a substance that is formed as a result of a chemical reaction.

Front

How can you determine if a chemical reaction has occurred?

Back

Signs of a chemical reaction include color change, gas production, temperature change, and the formation of a precipitate.