Chemical Reactions

What is the difference between reactants and products?

• Reactants are the substances that undergo a chemical reaction, while products are the substances that are formed as a result of the reaction.

• Reactants are the substances that are formed as a result of a chemical reaction, while products are the substances that undergo the reaction.

• Reactants and products are the same thing.

• There is no difference between reactants and products.

Name three properties that can be observed in a substance.

• Color, taste, and smell

• Density, boiling point, and melting point

• Weight, volume, and temperature

• Shape, size, and texture

Name three properties that can be observed in a substance.

• Color, taste, and smell

• Density, boiling point, and melting point

• Weight, volume, and temperature

• Shape, size, and texture

What is the Law of Conservation of Matter, and how does it apply to chemical reactions?

• The Law of Conservation of Matter states that matter cannot be created or destroyed in a chemical reaction. It applies to chemical reactions by ensuring that the total mass of the reactants is equal to the total mass of the products.

• The Law of Conservation of Matter states that matter can be created or destroyed in a chemical reaction. It applies to chemical reactions by allowing the mass of the reactants to change.

• The Law of Conservation of Matter states that matter can be created or destroyed in a chemical reaction. It applies to chemical reactions by ensuring that the total mass of the reactants is equal to the total mass of the products.

• The Law of Conservation of Matter states that matter cannot be created or destroyed in a chemical reaction. It applies to chemical reactions by allowing the mass of the reactants to change.

True or false: A physical change results in new substances being formed.

• True

• False

If you have 12 atoms of hydrogen before a chemical reaction, how many atoms of hydrogen will be present after the chemical reaction?

• 6 atoms

• 12 atoms

• 24 atoms

• It depends on the specific reaction.

Why does the mass of a substance remain the same after a chemical reaction?

• Because matter cannot be created or destroyed in a chemical reaction.

• Because the mass of the reactants is always equal to the mass of the products.

• Because the mass of a substance is independent of chemical reactions.

• Because the Law of Conservation of Matter does not apply to chemical reactions.

How does a catalyst affect a chemical reaction?

• A catalyst increases the rate of a chemical reaction.

• A catalyst decreases the rate of a chemical reaction.

• A catalyst has no effect on the rate of a chemical reaction.

• A catalyst stops a chemical reaction from occurring.

Give an example of a chemical reaction during which a single substance breaks down.

• Burning of wood

• Melting of ice

• Boiling of water

• Decomposition of hydrogen peroxide

How can scientists use their knowledge of chemical reactions?

• To develop new materials and medicines

• To understand the behavior of substances

• To solve environmental problems

• All of the above