Law of Conservation of Mass Review

If there is 200 g of reactants, how many grams of products should there be?

• Less than 200 g

• Equal to 200 g

• More than 200 g

Tags

NGSS.MS-PS1-5

Does this follow the law of conservation of mass?

• Yes, because there are the same number of atoms.

• Yes, because there are not the same number of atoms.

• No, because there are the same number of atoms.

• No, because there are not the same number of atoms.

Tags

NGSS.MS-PS1-5

Does this equation follow the law of conservation of mass?

• Yes, because the mass is the same.

• Yes, because the mass is not the same.

• No, because the mass is the same.

• No, because the mass is not the same.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which equation follows the law of conservation of mass?

• Na + Cl₂ --> NaCl

• Na + Cl₂ --> 2NaCl

• 2Na + Cl₂ --> NaCl

• 2Na + Cl₂ --> 2NaCl

Tags

NGSS.MS-PS1-5

Suppose 20 g of liquid hydrogen peroxide is heated so it completely breaks down into liquid water and oxygen gas. Which best describes the total mass of the water and oxygen that was produced?

• more than 20 g because of the addition of heat

• more than 20 g because there are now two substances

• less than 20 g because oxygen gas is very light

• 20 g because no matter is added or removed

Tags

NGSS.MS-PS1-5

According to the law of conservation of mass, how much zinc was present in the zinc carbonate?

• 104 g

• 88 g

• 110 g

• 40 g

Tags

NGSS.MS-PS1-5

Students react baking soda & vinegar.
Which of the following would provide the evidence that the number of atoms present before a chemical reaction is equal to the number of atoms present after the chemical reaction?

• The mass of the plastic bag, baking soda, and vinegar before the reaction was equal to the mass after the reaction.

• Bubbles were produced during the reaction, which meant that a gas was being produced.

• The plastic bag did not change in any way, indicating that it was not involved in the reaction.

• The mass of the baking soda was exactly equal to the mass of the vinegar used to create the chemical reaction.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which diagram best demonstrates the law of conservation of mass?

• 
• 
• 
• 

Tags

NGSS.MS-PS1-5

Which statement best describes the law of conservation of mass?

• Mass is created during a chemical reaction.

• Mass is destroyed during a chemical reaction.

• Mass is neither created nor destroyed during a chemical reaction.

• Mass is always increased during a chemical reaction.

Tags

NGSS.MS-PS1-5

In a closed system, 50 g of reactant A reacts with 30 g of reactant B. What is the total mass of the products?

• 80 g

• 50 g

• 30 g

• 100 g

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5