Chemical Reactions

Which of the following models best demonstrates a balanced chemical equation?

• F
• G
• H
• J

Tags

NGSS.MS-PS1-5

Which of the following equations demonstrates an actual chemical reaction that forms a new substance?

• A
• B
• C
• D

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Two clear colorless solutions were combined.
The student observed that the temperature changed from 25 •C to 23 •C when the solutions were combined and that a white substance rapidly formed and settled to the bottom of the container. What most likely happened to produce these results?

• One of the original compounds came out of solution
• The solutions reacted chemically
• Some of the water froze into ice crystals
• Rapid evaporation of water occurred, leaving a solid

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-4

In which of these compounds are there twice as many oxygen atoms as hydrogen atoms?

• H₃PO₄
• H₂SO₄
• HCIO₃
• H₂0

Tags

NGSS.MS-PS1-1

In a ___________change, a substance changes into a different substance.

• Physical

• Chemical

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

The Law of Conservation of Mass states

• that matter exists in all states and reacts the same

• that matter can only be changed into new substances by introducing a catalyst

• that matter exists in the same state throughout any chemical change

• that matter cannot be created or destroyed and that the mass of the products must equal the mass of the reactants

Tags

NGSS.MS-PS1-5

a copper penny turning greenish after a few years.

• Physical change

• Chemical change

Tags

NGSS.MS-PS1-2

___________________ are the elements or compounds that leave (are formed in) a chemical reaction.

• Polymers

• Bonds

• Reactants

• Products

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Increasing the concentration of a reactant in a chemical reaction will _____________.

• decrease the rate of the reaction
• stop the reaction from happening
• increase the rate of the reaction
• have no effect on the rate of the reacion

Tags

NGSS.HS-PS1-5

How do chemical reactions turn substances into new substances?

• with burning acid
• the molecules mix together and create new substances
• the atoms break apart and combine back together in new ways
• the ionic compounds mix in water to form solutions

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5