Lesson 3: Energy Changes and Chemical Reactions

Multiple Choice

What is the significance of energy changes in chemical reactions?

• They determine whether a reaction will occur spontaneously

• They only affect the temperature of the surroundings

• They are not important in chemical reactions

• They only occur in laboratory settings

Multiple Choice

Which type of reaction absorbs energy: endothermic or exothermic?

• Endothermic

• Exothermic

• Both

• Neither

Multiple Choice

Which statement best describes the role of activation energy in chemical reactions?

• It is the energy required to start a reaction.

• It is the energy released during a reaction.

• It is the energy stored in the products.

• It is the energy lost to the surroundings.

Multiple Choice

Which of the following factors increase the rate of a chemical reaction?

• Increasing surface area

• Decreasing temperature

• Lowering concentration

• Reducing pressure

Multiple Choice

Which of the following statements best describes the difference between exothermic and endothermic reactions?

• Exothermic reactions absorb energy, while endothermic reactions release energy.

• Exothermic reactions release energy, while endothermic reactions absorb energy.

• Both exothermic and endothermic reactions absorb energy.

• Both exothermic and endothermic reactions release energy.

Multiple Choice

Which of the following best describes the role of inhibitors in medicines and food preservatives?

• They speed up chemical reactions in bacteria and food.

• They attach to enzymes and keep them working properly.

• They slow down or stop chemical reactions by attaching to enzymes.

• They destroy all enzymes in the body.