1.4.2 Energy Changes

• What happens to chemical potential energy in an exothermic reaction?

  It decreases
• Endothermic reactions absorb energy from the surroundings
• Match the feature with the correct state in an endothermic reaction:

  Chemical Potential Energy ↔️ Higher in Products

  Energy Absorbed ↔️ Yes

  Surroundings Temperature ↔️ Decreases
• Endothermic reactions cause the temperature of the surroundings to decrease
• Endothermic reactions cause the surroundings temperature to decrease.


  True
• What does the x-axis represent in an energy profile diagram?

  Reaction progress
• What does the y-axis represent in an energy profile diagram?

  Energy
• Match the type of reaction with the slope of its energy profile diagram:

  Exothermic ↔️ Downward

  Endothermic ↔️ Upward
• The surroundings temperature decreases in an endothermic reaction.

  True
• In endothermic reactions, the products have higher chemical potential energy than the reactants.

  True
• Compare exothermic and endothermic reactions based on energy transfer and temperature change:

  1️⃣ Exothermic reactions release energy, causing the surroundings' temperature to increase

  2️⃣ Endothermic reactions absorb energy, causing the surroundings' temperature to decrease
• In energy profile diagrams, the x-axis represents the progress of the reaction.


  True
• Match the type of reaction with its corresponding energy profile diagram feature:

  Exothermic ↔️ Downward slope

  Endothermic ↔️ Upward slope
• Exothermic reactions have a negative enthalpy change ($\Delta H < 0$).


  True
• What does the enthalpy change ($\Delta H$) measure in a reaction?


  Energy difference
• Match the type of reaction with its example:

  Exothermic ↔️ Burning wood

  Endothermic ↔️ Melting ice
• Exothermic reactions result in products with higher chemical potential energy than reactants.

  False
• Endothermic reactions absorb energy from the surroundings.


  True
• In endothermic reactions, the temperature of the surroundings decreases
• What does the x-axis represent in an energy profile diagram?

  Reaction progress
• In endothermic reactions, the products have more chemical potential energy
• What does the x-axis represent in an energy profile diagram?

  Reaction progress
• Exothermic reactions release energy to the surroundings.

  True
• Dissolving ammonium nitrate in water is an example of an endothermic reaction.


  True
• Exothermic reactions release energy, indicated by a negative enthalpy change.
• The surroundings temperature increases in an exothermic reaction.


  True
• What happens to chemical potential energy in an endothermic reaction?

  It increases
• What happens to chemical potential energy in an exothermic reaction?

  It decreases
• Match the feature with the correct state in an endothermic reaction:

  Chemical Potential Energy ↔️ Higher in Products

  Energy Absorbed ↔️ Yes

  Surroundings Temperature ↔️ Decreases
• Exothermic reactions release energy because the products have lower chemical potential energy than the reactants
• Exothermic reactions have a downward slope on an energy profile diagram.

  True
• Energy is absorbed in endothermic reactions, resulting in an upward slope on the energy profile diagram.

  False
• Exothermic reactions release energy and have products with lower chemical potential energy than reactants.


  True
• Endothermic reactions absorb energy from the surroundings
• In endothermic reactions, energy is absorbed from the surroundings, causing its temperature to decrease
• The surroundings' temperature in an endothermic reaction decreases
• What is an example of an exothermic reaction?

  Burning wood
• For endothermic reactions, the energy profile diagram has an upward slope.
• What is activation energy?

  Minimum energy to start a reaction
• Endothermic reactions have a positive enthalpy change (\Delta H > 0</latex>).

  True