Chemical Reactions & Conservation of Mass

According to the law of conservation of mass, which of the following is a TRUE statement about any chemical reaction?

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

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

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

• In a chemical reaction, matter can be created but not destroyed.

Tags

NGSS.MS-PS1-5

Match the following

• CH4

• Reactant

  Compound

• CO2

• Product

  Compound

• 2C2

• Reactant

  Element

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

NGSS.MS-PS1-1

How many elements does PbNO₃ have?

• 2
• 3
• 4
• 5

Tags

NGSS.MS-PS1-1

How many nitrogen atoms does NH₃ have?

• 1
• 2
• 3
• 4

Tags

NGSS.MS-PS1-1

Each substance written to the LEFT of the arrow in a chemical equation is a ____.

• reactant

• product

• precipitate

• catalyst

Tags

NGSS.MS-PS1-5

What is a group of atoms bonded together?

• products

• consumer

• molecule

• reactants

Tags

NGSS.MS-PS1-1

Which of the following is an example of a chemical reaction?

• A marshmallow turning black when heated over a fire
• A powder dissolving in water to make lemonade
• An ice cube melting into a puddle of water
• Salt crystals being crushed into a powder
  

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

What happens when chemical bonds break and new bonds form?

• a physical change
• a chemical reaction
• matter is destroyed
• surface area increases
  

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

When heated, oxygen reacts with copper to form copper oxide:
If this reaction occurs in a sealed container, will the mass of the container and everything in it increase, decrease, or stay the same and why?

• The mass will stay the same because the number of each kind of atom stays the same.
• The mass will increase because a new kind of molecule is formed.
• The mass will decrease because two substances combine to form one substance.
• More information is needed to tell if the mass will change.
  

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

Identify the reactant(s) and product(s) of the reaction.

• All three are reactants and none are products.
• Hydrogen and water are the reactants, and oxygen is the product.
• Water and oxygen are the reactants, and hydrogen is the product.
• Hydrogen and oxygen are the reactants, and water is the product.