A student combines 25 g of sodium and chlorine. The product is 80 g. How much chlorine was used?

• 25 g

• 55 g

• 80 g

• 105 g

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

According to the Law of Conservation of Mass, what must be true in a chemical reaction?

• The total mass of reactants equals the total mass of products.

• The mass of products is always greater than the reactants.

• The mass of reactants is always less than the products.

• Mass is not conserved in chemical reactions.

Tags

NGSS.MS-PS1-5

If a reaction starts with 40 g of reactants and produces 35 g of product, what can you infer?

• 5 g of product was lost or not measured.

• The law of conservation of mass does not apply.

• The reaction created extra mass.

• The product is heavier than the reactants.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

If 60 g of reactants are used in a reaction, what should be the mass of the products according to the law?

• 60 g

• 30 g

• 90 g

• 120 g

Tags

NGSS.MS-PS1-5

If a chemical reaction in a closed system starts with 100 g of reactants, what will be the total mass of the products?

• 100 g

• 50 g

• 150 g

• 200 g

Tags

NGSS.MS-PS1-5

A student mixes 20 g of magnesium with oxygen. The product is 44 g. How many grams of oxygen combined?

• 20 g

• 24 g

• 44 g

• 64 g

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

A reaction produces 75 g of product. One reactant is 30 g. How much is the other reactant?

• 30 g

• 45 g

• 75 g

• 105 g

Tags

NGSS.MS-PS1-5

A teacher puts 200 g of reactants into a closed container. After the reaction, the container and products together weigh 200 g. What does this show about the Law of Conservation of Mass, and why is using a closed container important?

• It shows new mass was created; the closed container doesn’t matter

• It shows mass is conserved; the closed container prevents gas from escaping

• It shows mass is destroyed; the container adds weight

• It shows energy is conserved, not mass

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

What is the mass of the products and container after a reaction if 200 g of reactants are used in a closed container?

• 100 g

• 0 g

• 200 g

• 400 g

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

What is a possible source of error in a conservation of mass experiment?

• Using a closed container

• Measuring mass before and after the reaction

• Allowing gases to escape from the container

• Using accurate scales

Tags

NGSS.MS-PS1-5