3.1 What happens when fuels burn? Chemical Reactions

What do fuels release when they burn?

• Water

• Carbon dioxide

• Energy

• Oxygen

What is the fuel used in most car engines?

• Hydrogen

• Ethanol

• Gasoline

• Diesel

What law did Antoine Lavoisier help come up with?

• Law of Conservation of Matter

• Law of Conservation of Energy

• Law of Gravity

• Law of Motion

What happens to the atoms in a chemical reaction?

• They disappear

• They rearrange into new groups

• They stop existing

• New atoms appear

What are the products when ethanol burns?

• Carbon monoxide and hydrogen

• Ethanol and water

• Hydrogen and oxygen

• Carbon dioxide and water

What is a characteristic of hydrogen fuel compared to gasoline?

• It is more harmful to Earth's climate

• It does not contain carbon

• It is a solid

• It contains carbon

What is the main challenge in using hydrogen as a fuel for vehicles?

• It produces carbon dioxide

• It is not effective

• It is expensive and difficult to store

• It is too abundant

What substance is made when hydrogen burns?

• Ethanol

• Oxygen

• Water

• Carbon dioxide

Why can't we see the substances formed when gasoline burns?

• Because they are solid

• Because they are invisible gases

• Because they are absorbed by the car

• Because they are too small

What does the Law of Conservation of Matter tell us about chemical reactions?

• All of the atoms that go into a chemical reaction come out in some form

• Atoms can be destroyed during chemical reactions

• New atoms appear out of nowhere during chemical reactions

• Matter can be created during chemical reactions