Law of Conservation of Mass Guided Notes

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Multiple Choice

If reaction starts with 20g of reactants it should produce 

• a total of 40g of products

• a total of 10g of products

• a total of 80 g of products

• a total of 20g of products

Multiple Choice

Matter can not be created nor destroyed: it can only be

• Destroyed a little bit

• Invisible

• Transformed, changed

• None of the above

Multiple Choice

Which of the models of a chemical reaction best represents the Law of Conservation of Mass?

• A

• B

• C

• D

Multiple Choice

A student pours 5.49 g hydrochloric acid (HCl) into an open beaker that contains a piece of magnesium (Mg). The Total mass of the product is 5.73 g. What was the mass of the magnesium?

• 5.71 g

• 11.22 g

• 0.24 g

Multiple Choice

A student heated a 10 gram sample of a chemical in an open container. A chemical reaction occurred, and the mass of the sample was measured again. The mass of the sample was found to be less than before the reaction. Which of the following best explains the decrease in mass of the sample?

• The heat caused the chemical to become less dense.

• The reaction gave off more heat than was added.

• Some of the lighter particles were destroyed.

• Some of the particles escaped as a gas formed.

Multiple Choice

A student dissolved 25 grams of salt into 1,000 grams of water. What should the mass of the saltwater mixture be?

• 975 grams

• 1,000 grams

• 1,025 grams

• 2,500 grams

Multiple Choice

In a reaction A + B ----> C,  reactant A has 5g and product  C has 9g. How many grams does reactant B should have? 

• 4g

• 5g

• 9g

• 14g

Multiple Choice

What will happen to the mass of the product if I double the mass of the reactants?

• It will decrease by half.

• It will increase by half.

• It will double in amount.

• The mass remains the same.

Multiple Choice

The Law of Conservation of Mass States

• Energy cannot be created nor destroyed, it can only change form.

• Mass cannot be created nor destroyed, it can only change form.

• Mass can be created or destroyed, it cannot change form.

Multiple Choice

Anything that has mass & takes up space

• gravity

• force

• matter

• volume