Quiz 2: Chemical Changes and Reactions

What is a physical change?

• A change that requires energy

• A change that involves a color change

• A change that alters the form or appearance of a substance

• A change that produces new substances

What are substances that undergo chemical changes called?

• Compounds

• Products

• Reactants

• Elements

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

• Melting ice

• Boiling water

• Crushing a can

• Burning wood

What type of reaction absorbs energy?

• Synthesis reaction

• Combustion reaction

• Endothermic reaction

• Exothermic reaction

What is the minimum amount of energy needed to start a chemical reaction called?

• Thermal energy

• Activation energy

• Kinetic energy

• Potential energy

What is produced when vinegar and baking soda react?

• Carbon dioxide gas

• Hydrogen gas

• Oxygen gas

• Nitrogen gas

Which factor does NOT affect the rate of a chemical reaction?

• Color of the reactants

• Concentration

• Temperature

• Surface area

What is a catalyst?

• A substance that slows down a reaction

• A type of reactant

• A substance that speeds up a reaction

• A product of a reaction

What happens to the energy in an exothermic reaction?

• Energy is absorbed

• Energy is released

• Energy remains constant

• Energy is created

What is a precipitate?

• A color change in a substance

• A type of catalyst

• A solid formed from liquid reactants

• A gas produced in a reaction