Unit 15: Thermochemistry

• What is energy?
• Why are some things more explosive than others?
• Can any reaction occur?
• If everything tends toward lower energy what does that predict about the future of the universe?

Unit outline

1. Whether or not a reaction requires a consistent input of energy depends on two factors - the change in potential energy and the change in entropy (energy dispersal).
2. The natural tendency in the universe is for a decrease in energy and an increase in entropy.

• Draw and interpret energy diagrams
• Write and interpret thermochemical equations for chemical reactions
• Use enthalpy change to classify reactions as exothermic and endothermic reactions.
• Calculate enthalpy change using
  • a. Energy diagrams
  • b. Calorimetry
  • c. Hess's Law
  • d. Heats of formation
• Define entropy and determine whether an increase or decrease in entropy occurs for a given reaction.
• Define spontaneous
• State that negative values of deltaH and positive values of deltaS are associated with spontaneous reactions
• Calculate Gibbs Free Energy to identify spontaneous reactions
• Compare and contrast various possible sources of energy and the consequences to the environment of using these sources

• Enthalpy and Energy Diagrams
• Thermochemistry
• Entropy and Gibbs Free Energy

• Hess's Law Worsheet
• Review Sheet
• Review Sheet Answers
  
  

  Practice

• Endothermic/Exothermic Reaction Lab
• Exothermic vs. Spontaneity Discrepancy Lab
• Heat of Solution