Law of Conservation of Mass

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

• Destroyed a little bit
• Invisible
• Transformed, changed
• None of the above

Tags

NGSS.MS-PS1-5

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

Tags

NGSS.MS-PS1-5

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

• A

• B

• C

• D

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

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.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

What is the left part of a chemical equation called?

2H₂ + O₂ ---> 2H₂O

• Reactants

• Yields

• Products

• Chemical equation

What is the right part of a chemical equation called?

2H₂ + O₂ ---> 2H₂O

• Reactants

• Yields

• Products

• Chemical Equation

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

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

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

Tags

NGSS.MS-PS1-5

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

• A

• B

• C

• D

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

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

• A

• B

• C

• D

Tags

NGSS.MS-PS1-5