5.P.2.2 Flashcard (Conservation of Mass)

Front

What is the Law of Conservation of Mass?

Back

The Law of Conservation of Mass states that mass is neither created nor destroyed in a chemical reaction. The total mass of the reactants equals the total mass of the products.

Front

If you start with 10 grams of a substance, what will be the mass of the substance after a chemical reaction?

Back

10 grams, because the mass is conserved.

Front

What happens to the mass of a balloon when the gas inside is heated?

Back

The mass of the balloon stays the same because the gas inside the balloon still has the same mass after it warms up.

Front

What is an example of a physical change?

Back

Melting ice is a physical change; the mass remains the same before and after melting.

Front

What is an example of a chemical change?

Back

Burning wood is a chemical change; the mass of the products (ash, smoke, gases) is less than the original mass of the wood.

Front

What happens to the mass of cheese when it is melted?

Back

The mass of the cheese remains 500 grams because it does not gain or lose mass just because it was melted.

Front

If a reaction starts with 30 grams of reactants, what should the total mass of the products be?

Back

30 grams, according to the Law of Conservation of Mass.

Front

What is the mass of a boiled egg if it started at 55 grams?

Back

55 grams, because boiling does not change the mass of the egg.

Front

What is the mass of a solution if 5 grams of salt is dissolved in 10 grams of water?

Back

15 grams, because the mass of the solution is the sum of the mass of the solute and the solvent.

Front

What is a reactant in a chemical reaction?

Back

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