Ch.5 Chemical Reactoins

Chemistry is

• a characteristic of a substance that can be observed without changing the substance into another substance

• the study of matter and how matter changes

• anything that has mass and takes up space

• a rapid reaction between oxygen and a substance called a fuel

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NGSS.MS-PS1-1

NGSS.MS-PS1-5

The only sure evidence for a chemical reaction is

• the formation of a gas

• a color change

• the production of one or more new substances

• changes in particles

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NGSS.MS-PS1-2

A material used to decrease the rate of a chemical reaction is a(n)

• inhibitor

• catalyst

• enzyme

• fuel

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NGSS.HS-PS1-5

CaCo₃ represents a chemical

• symbol

• formula

• subscript

• reaction

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NGSS.MS-PS1-1

Which is the correct chemical equation for the following statement? Sodium reacts with oxygen in a 2 to 1 ratio to produce sodium oxide

• 4 Na + O₂ --> 2 Na₂O

• 2 Na + O₂ --> 2NaO

• Na₂O + O₂ --> 1 NaO

• Na₂ + O₂ --> Na₂O₂

Tags

NGSS.MS-PS1-5

The principle of conservation of mass is true

• only for reactions that take place in open systems

• only for reactions that take place in closed systems

• for reactions in both open and closed systems

• for no reactions at all

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NGSS.MS-PS1-5

In the chemical reactions, what does the principle of conservation of mass mean?

• Matter is not created or destroyed

• 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

• Matter is not changed

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NGSS.MS-PS1-5

Chemicals that act as biological catalysts by speeding up reactions in living things are called

• inhibitors

• enzymes

• fuels

• reactants

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NGSS.MS-LS1-7

Which of the following is an example of how to supply activation energy to begin a reaction?

• Cool the reaction flask in an ice bath

• Add a catalyst

• Heat the reaction flask on a hot plate

• Add an inhibitor

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NGSS.MS-PS3-3

A bottle of hydrogen peroxide that eventually turns into a bottle of water and oxygen gas is an example of a

• synthesis reaction

• decomposition reaction

• replacement reaction

• precipitate reaction