Energy Changes in Chemical Reactions

What is the minimum amount of energy required for particles to react with each other?

• Activation energy
• Thermal energy
• Kinetic energy
• Potential energy

Which of the following is NOT an example of an exothermic reaction?

• Combustion

• Neutralisation

• Thermal decomposition

• Oxidation

According to the text, what is the relationship between the energy needed to break bonds and the energy released when bonds are formed in an exothermic reaction?

• The energy needed to break bonds is greater than the energy released when bonds are formed.
• The energy needed to break bonds is equal to the energy released when bonds are formed.
• The energy released from forming new bonds is greater than the energy needed to break existing bonds.
• The energy released from forming new bonds is less than the energy needed to break existing bonds.

What is the primary reason why energy changes are significant in chemical reactions?

• They determine the rate of a reaction.

• They influence the formation of new substances.

• They are responsible for the colour changes observed in reactions.

• They are the basis for all chemical reactions.

Which of the following is an example of an everyday application of an endothermic reaction?

• A self-heating can
• A hand warmer
• A sports injury pack
• A battery

What is the relationship between bond breaking and bond formation in terms of energy changes?

• Energy is always released when bonds are broken and absorbed when bonds are formed.
• Energy is always absorbed when bonds are broken and released when bonds are formed.
• Energy is released when bonds are broken and absorbed when bonds are formed.
• Energy is absorbed when bonds are broken and released when bonds are formed.

What is the purpose of using reaction profiles in the study of chemical reactions?

• To predict the products of a reaction.

• To determine the rate of a reaction.

• To visualise the energy changes involved in a reaction.

• To calculate the activation energy of a reaction.

What is the significance of the activation energy in a chemical reaction?

• It determines the rate of a reaction.
• It determines the overall energy change of a reaction.
• It determines the type of products formed.
• It determines the temperature at which the reaction occurs.

Explain how energy is conserved in chemical reactions, as described in the text.

What is the difference between an exothermic and an endothermic reaction in terms of energy transfer?